you definitely received a treasure there and I don't mean the money value.
I would probably start first with deciding how you want to do your belts/wallets/straps and go from there. Will you be doing any tooling? Minimal? Lots? Then look at the different designs of each and decide on the style you want to go with for each. If you aren't tooling, then you need to decide on what kind of leather you want to use.
If you decide you are going to be doing tooling, get some of the rounders and use those to practice different things on.
Above all else, do lots of reading and practice and don't be afraid to post in the critique section for a second set of eyes to help find things you might miss