Looks good for a first attempt... jetpacks are a hard thing to paint, and with all the masking and everything, it is a daunting task even for people with far more experience.
On that note, it looks good but the lines COULD be a little cleaner especially with regards to the light blue. Would I worry about repainting it right now, no, but for future reference just watch the lines and what tape you use to mask could make a HUGE difference.
Again, good job dude!