Its a pain in the ass to do it correctly. Besides purchasing and mixing the correct paints and hardeners, you'll need masks and decent compressors (some suck). There is also the prep work (cleaning, sanding), the actual painting (then more sanding), the layering, etc etc etc....

Bear in mind that all of this is in addition to knowing wtf you are doing (translation: even with all the right stuff you might still screw it up).

Its not that painting itself is difficult... it is just a labor intensive job that takes time and effort/experience to do it satisfactorily.

I would only considering doing it if you plan to start doing it as a hobby or side business or something (or have a friend with stuff who can help you learn). Its not worth the effort for a once-in-a-while thing like a bike.