First time painting, have some questions about respraying

I sprayed my car last june for the first time. Its nowhere near perfect and this summer I wanted to respray it. I've taken a few highway trips and realized theres a ton of paint chips in my hood which totally sucks. I originally used a single stage paint just for the simplicity, but when I go to do it again, can I clear coat it also? I plan on just using the leftover paint from lastyear. And am I supposed to spray the clearcoat after its fully dry or just spray it within the 10-15min coating timeframe. Thank you!