Buy all 10 squad members. That will eat up most of your 1800. After that, just start unlocking every gun/attachment/kill streak per soldier.
The Prestige process is to both unlock and complete Level 60 for each Soldier a total of 10 times (Prestige Master); highlight and press F2 to select the next Soldier and a yellowish 'star' will indicate your selected Soldier. So as stated Unlock a Soldier, Prestige (level 60 done) and move on to the next. At minimum it will cost ~150+ Squad Points to unlock and populate all 6 Classes. The last two Soldier unlocks (Prestige 9 & 10) themselves cost 400 and 500 points plus the cost to populate the classes per each.
Once you're Prestige Master the Squad Points are essentially irrelevant. I'm one Soldier away from Max Prestige (Prestige 9 Level 60 but some XP is still needed). So in one regard my ASSUMPTION ... as in some prior CoD's once you're Master Prestige everything for your 'Soldiers' is unlocked and no Tokens are needed. However, at this point I don't know yet...
Based upon the past , once a Prestige Master both Tokens and XP are 'meaningless' ... pff other than Leaderboard positions (XP, Kills, Scores, etc) which are hacked all to hell!