Don't waste your money on a class. Being an airsmith is like being a rock star. It's what you want to be when your young. Then you realize it doesn't pay that great no matter who you work for. Buy tech videos. Some are very good. Watch them and learn from them. Buy broken markers and fix them (if you have the time). I normally do that but find myself selling them when they are finished or almost finished. I research what I want to buy then hit the local field or internet looking for that certain marker for very cheap. By the time I find that marker,I either own the video or have all the info needed to repair it. You can make more money on the side than you can working at a shop. Hope this helps.
NOTE: If you decide to take a class here is a suggestion. I guess alot of tourney teams are getting "pit crews". You know the ones who look up to these idiots (not every tourney player is). Find out what they shoot. Offer you services at a fee,no free. Paintballs from their sponsers isn't payment or promises they will let you try out. Cold hard cash. If they are that good then their sponser will pay or they will.