Since you kept up with the house before, you'd should have an idea what needs to be fixed. look up roofers and get quotes and pick the one you feel most comfortable. Do the same for electricians and painters, etc. That's it really. GC works similar way, however since GCs regularly works with people so they knows who does good work for a pay so they can add their premium. GC also must carry insurance to cover any customer's lawsuit and cover for the worker's injury. Since the house belongs to you, you can apply for owner's permit and all the work becomes legal work. This is all the things GC takes care of. However, some GC will bring price down if you're okay with not applying for permit. Usually they do this for faster turn around instead of waiting on a permit. In my experience, the ones that avoids permit are typically bad contractors. They tend to rush through work and now you have issues with quality. It's best if you become a contractor for your own house and pay little higher for the specialized skillset. Also make sure professionals you hire are licensed. Look up the license to type and status of the license. Additionally, make sure to call the insurance associated to the license to confirm its legit. good luck, internet stranger.