First of all, you're super lucky to get a 5* from a premium ticket! Congrats! Joachim is also a pretty strong card, so you lucked out there as well.
Check out our Encyclopaedia section and the FAQ sticky in Game Discussion for random information/tips about the game. I would not suggest trading your card unless you have someone trustful helping you out with prices/good trades, at least for now.
Welcome to the forums. (: