I think it's a great idea and I'm glad you are thinking ahead and realize it will be many years before your idea pans out. I can't give you any specific advice but I think advice others have given is good. I don't see any need for the throat jumping since you are obviously not planning on doing this any time soon. One bit of advice I can give you...major in something in college related like biology or zoology. And for your electives, take a couple business courses. You're going to need to know a lot about managing your funds and raising money, and especially if you want to incorporate into a non-profit business courses will help you. For now I think it would be a great idea for you to volunteer with a reptile rescue and get exposed to all of the behind the scenes stuff plus you will learn tons about animals you might not have ever dealt with.
I think we ought not to jump down the throat of everyone who wants to be a reptile rescue. Everything starts with an idea, sure the idea may need a lot of work and tweaking but that's why CyberGhost posted this in the first place. Frankly there aren't enough rescue centers for herps...mostly just dogs and cats. Its better for the herps if we can use this site right and help someone with this idea get it off the ground someday the right way. Not saying that everyone who wants to rescue has the best intentions in mind but not everyone who does want to start a rescue just wants free herps.