Welcome to the hobby. No need to take a class. The best resources are on the web, including this site. The most important tool in your arsenal is patience and a willingness to learn. Nine years ago, I bought my first pin with no knowledge of anything, and now I have 16 and am able to repair almost any issue.

As others have mentioned, you will need basic tools, like a multimeter, soldering iron, screw drivers, nut drivers, wrenches, etc. They are all things you can pick up at Home Depot.

Take the plunge and buy a game you like. If it is an older game (1990's) then you will probably need to do some maintenance/repair on it. It is not rocket science. Anyone with patience can do it.

Here are some excellent resources. I suggest you study these carefully. They have a ton of useful info. If they are useful, please make a donation to those to keep them running (I am not affiliated with them in any way).

http://www.pinwiki.com
http://www.pinrepair.com/begin/index.htm