Tttaylorrr,
Good luck!
I think a poop sample will get you 95% of what you want to know.
In my experience, most things that will come up in a poop sample can be treated and fairly easily, like parasites.
The more you know the better you are. Just be prepared to get Corny what he needs and make sure they show you how to administer any treatment if they aren't going to do it for you. If you are expected to do it, let them show you and have you do it at the vet, so you feel comfortable.
Good luck again and keep us in the loop!