I would suggest you practice many times on a piece of scrap metal before you ruin a $4,000 scoot/moped.
Take your time, sand down the existing paint, and practice giving it coats, go slow, learn to adjust the distance of the spray head so you don't make drips or runs in the painted area. If you get a drip, become more patient and use more space between the nozzle and the surface being painted. It's easy to want to rush the job and get the parts back together, resist this temptation at all costs or you'll be paying someone to paint it for you.
It sounds like your a novice (so am I) I'd take the parts off to be painted to a shop and ask them to paint them for me, you might even save some money not to mention time and frustration.