little question

ok i finished painting my Challenger but it has some little bubbles on it nothing much but is it safe to sand it out when it has dryied only 2days? or just leave the model that way?

Sounds like you may have still had some mold-release on the body, or it was extremely humid.
If you are OK with the bubbles, leave them! If you want it to be better, you'll have to strip the paint and start all over
:(
Think of it as "character building" :D