I do not recommend using the javelin (jav) until you are decent at warbird (1.4 kills to 1 death), played in ?go javs for 5 hours and have atleast 100 in game hours. This is because too many players in pub get into a jav, go into the flag room (fr) and get more team kills (tks) than kills. There is a tendency for pub javs to not care about tks, or think if they get atleast 1 enemy then it doesn't matter how many tks they get.
Strategies:A jav in pub is only useful in the base or attacking fr from the top of base. There are many "shots" that pub javs can use. The best way to learn shots is by watching other javs and practicing in a private arena (anything with a # before it, example: ?go #prac). Knowing shots is step 1 to becomming a decent pub jav. Step 2 is being able to predict where a bomb will go if you were to shoot on the fly.
Be careful not to tk, especially if you don't get an enemy kill or it was unnecessary (a lone enemy spider in fr with 3 spiders from your team).