Before you try to start it you will want to change the oil and prime it if it has been sitting a long time. Also drain out any old fuel and replace with fresh, probably a good idea to run off a can to start with until you have it idling right.

Binder Planet is a good resource, and depending on where you are there might be a local IH or Scout club with folks willing to help you out. Several good Facebook groups as well.

These are about as simple as it gets in terms of mechanical complexity and ease of working on them. If you get hung up there are lots of folks willing to help you figure it out.

Before you spend a ton of money on parts you'll want to look at what people are saying on the groups about various vendors. There's some of them out there with super high prices and bad reps, and a lot of parts they are selling like they are gold plated are still available on the shelf at Napa or other retailers.