Why are you here then? To troll? This game will remain pretty active until Treyarch releases a new game which won't be for a couple more years.
To the OP, yes, learn the maps and practice. If you're new consider starting out in Combat Training.
Seriously, I've looked at your posts and you're nothing but a retarded troll. It's a shame the moderation is light here...
First, welcome to the game and the forums.
No matter what you hear in the forums, from friends, in rooms, or on you tube, the only way you need to play this game is the way that makes you happy. Don’t ever let anyone else tell you that you have to do something a certain way. I’m going to offer a lot of advice that I wish I had known about when I started. Take it or leave it in part or in whole.
Yes, learning the maps is very important and a huge advantage others have over you right now. Knowing where people like to hide waiting for someone to go past, knowing the routes most frequently taken, knowing the choke points where a lot of action takes place and knowing where people spawn will be a big help in reducing the frequency of you dying. Does someone typically sit in a certain room waiting for people to come in? Toss in a grenade before entering instead of just running in. Are you running down a path where people frequently spawn at a point that is now behind you? Take frequent looks behind you or get off the path entirely. As you learn the game, avoid the high congestion choke points where all the top players immediately sprint to. Stay along the outer edges of the map. It will give you less places to be aware of (no one can be behind you if your back is to the edge of the map,) and give you a bit better reaction times with only one or two directions you need to cover.
Style of play: Rusher (near-constant runner, uses light, fast guns, speed enhancing perks and hip shooting), Camper (near constant stationary, holds down a specific area of the map such as a popular route or game objective like a flag), Tactical Mover (moves from point to point sometimes fast, sometimes slow waiting for a kill or two before moving on. Don’t get sucked in to thinking you have to play one of these because of someone else’s opinion, what you see on You Tube or even that you have to play the same way every match.
Two things you do want to avoid are:
If you rush, don’t be a “headless chicken” - a person that just sprints full speed, never taking into account possible campers/snipers waiting for them, staying out in the open for long times, running in straight lines, relying solely on reflexes to win face to face gunfights. If you are dying a lot, there’s a good chance you have seen other people go sprinting off at the start of the game and become one of these. If you keep it up, be prepared to lead the room in deaths every game. Instead, move fast and near constantly, but use cover, know where people might be waiting in ambush and flank that area or grenade/flash bang the area before entering. Avoid running out in the open for long distances or in straight lines.
Conversely, if you are a camper ( includes snipers, LMG players using suppression fire, objective defenders with any weapon) do not become the guy that sits in a backwater corner of the map away from all the objectives, backed into a corner and ADSed (aimed down sight) at the only entrance to your hiding area. If you do, be ready to have the fewest kills and lowest score in the room every time. Instead, set yourself up in an area with a sniper rifle that overlooks the long path a headless chicken will run down, or a place that overlooks a choke point where the rushers are going to congregate for battle and pick them off. Set up a place where you can defend an objective from being taken by the enemy. Set up so the enemy cannot advance down a particular route to get to your team without being picked off.
Like I said before, you do not have to play one of these styles exclusively. Your play style can change by the map you’re on, the game type and by the way your opponents are playing. Are you up against a bunch of headless chickens? Set up camp on a main route and listen to them yell “camper!!” each time you shoot them as they come back again and again down the same path to be shot by you before they get close. Are they all camping against you? Be a smart rusher and flank them. If you know where he is, just lob in some grenades or for ultimate enjoyment, sneak around in back of him and stab him with a knife while he sits there staring down his scope where he THINKS you will come from.
Note that in either case you may have to adapt your load out of weapons and perks mid game to deal with your opponents. If you need to switch from camper to rusher or vice versa, be ready to do it.
Weapon Classes: Again, use them all. Not only will you learn which class you enjoy using, you will learn which classes go with which game styles. Once you know what a gun class does and its limitations, you can counter an opponent using that type of gun. For instance, if the other guy is using a shotgun, keep your distance and take him out at mid to long range with an A/R, LMG or sniper rifle. If he is using a sniper rifle, flank him and engage at short range with your shotty, smg or pistol.
Perks: Again use them all, but match them to weapon and play style. If you plan on holding down the main path from a distance with a sniper rifle, you don’t need a perk that will help you run fast or a long time. If you are running and getting killed a lot while you learn, you don’t need scavenger because you are not running out of ammo before dying. Think about how you plan to use a particular weapon and pick perks that augment that play style or that cover up a deficiency caused by that play style. I do suggest you watch some you tube videos about the perks since some of them do things you are probably not aware of. I also suggest you tube videos for the following category:
Attachments: Again, use a variety and change up your combinations to see which work well with a particular weapon. Different scopes have different fields of view and magnifications. Understand what affect using a stock has on different weapons, fore grips, pistol grips, etc etc. Some guns go from bad to good depending on the attachment and other guns in the same class (smg, ar etc) will have negligible or even negative affect from the same attachment. Attachments should again be matched to play style.
Score streaks: Start with the lower score needed streaks. UAV, drone and care package make a good starting combo since the points are low and the first two contribute points to the third, which has the chance of being something powerful. When you are getting 2 care packages per game, start swapping in more powerful score streaks, but keep in mind trying to “chain” them. Don’t pick K-9 just because you want it. It will be quite a while before you put together that kind of score streak without dying.
COMBAT: Everyone else mentioned practice. That is because when you start, you’re going to be slow remembering which button does what, how the mini map really works, recognizing what the enemy is up to and your accuracy is going to be low. In the standard games (core) it takes a LOT of bullets to kill someone. Some of that is the game itself not recognizing you hit someone, and some of it is game design so that once you start getting shot you can get away before you die. Because of that, accuracy plays a huge role in who lives or dies. If you have to come to a stop, aim down your sight and track the enemy by moving your gun barrel and your opponent can keep moving, even hopping around and hip firing with greater accuracy than you, you’re going to die. A lot. I strongly suggest you try at least a few games of hardcore as you learn. Your hit points, or life points or health is only 30% of what it is in core. While this sounds bad, it is actually good for a newbie. Since your enemy has the same limited health, you need fewer rounds on target in order to get a kill and with surprise on your side, you should get kills that you probably still wouldn’t in core. Also, the mini map is only useable by the enemy under certain circumstances which makes you less visible and gives you one less thing to concentrate on while figuring things out.
Perhaps the most common mistake I see new players make is running with the gun barrel pointed at the ground. If you are running and you notice the reticule is not pointed at chest level, change it so it is. By nature, we want it out of our field of view and we lower it so we can see well. In reality, we need it already pointed at the center of the screen so when we have a fast face to face encounter we can fire immediately and not have to wait for the gun barrel to rise from the dirt to the chest. That ½ second will get you killed before you get a shot off on target.
Ranking up fast:
Each weapon, attachment, perk, game type etc etc has points that can be earned in addition to the points you earn in a particular match. Go to BARRACKS then CHALLENGES and you will see all the different ways you can score additional points each match that do not show up in the game score, but do give you XP to level up. As your weapons are ranked up, more and better attachments become available. As YOU rank up, more weapons and perks become unlocked to use. Think about a particular challenge you are working on when choosing play style, weapon and load out (perks, attachments, grenades/mines, tacticals, etc) and you can maximize the points you will be earning each match.
Gun Classes: Try them all and not just a game or two. Give them a good go of things. This will do a few things for you. First you find out what classes you have fun with and/or are good at, second, you find out what type of gun is or is not good for a particular style of play (shotguns are great for close quarters combat (CQB) but suck at any kind of distance whereas a sniper rifle can kill at longer ranges than other guns, but is unwieldy at point blank ranges)
Play league mode, that's the only way you'll get good at the game. At first, you'll be sh!t. But once your team starts yelling & screaming at you, you'll learn fast.