Well, at some point you just got to jump in the deep end and go for it. It would help to meet people and have them show you what to look for. Don't over think it, though. If a game functions properly and looks well maintained then it's probably fine. Check boards for anything that looks hacked or battery corrosion. I made the mistake of overlooking that on one of my games and it end up costing me a lot in repairs. There will probably be a few things that need a little work but that's pinball. For your first pin, I would avoid projects or games with a lot of problems. If the flippers are weak or a switch is not working, those are easy to fix. It would help to learn pricing so you don't overspend. Condition determines price more than anything. If the playfield is worn out or plastics are broken and unobtainable, that affects price a lot.