You know, little makes me more sick than an experienced person trying to make an inexperienced person feel bad or small for not knowing something. What? Are you supposed to be born knowing EVERYTHING?!

So, if anyone gives you crap tell them to shove it.

You did what any REAL mechanic would do. Ask, when they don't know.

You don't need an engine hoist to change out the belts. There should be brackets with bolts that are used to tension each of the three belts. The AC belt MIGHT go around a tiny lower engine mount that is bolted to the subframe. If it does, you can remove that mount without problem. The Alternator might not have a bolt type tensioner depending on the engine. If the alternator doesnt have a bolt type tensioner you have to use a prybar or something to put tension on the belt as you tighten the lockdown bolt. Kind of a pain but not too hard. To tell if the belt is tight enough, push or pull on the longest length of the belt when its on and it should move either direction about a half an inch with moderate pressure. The belts dont have to be REALLY tight just tight enough. Make sure you tighten all of your bolts/nuts and you're good to go.

Replacing teh belts wont solve any running problems unless one is slipping. What are the symptoms of your running problem?