Ordinarily you can't sue a state at all unless they waive sovereign immunity. In cases where they waive it, you usually have to sue them in their own state courts and they have a bunch of other special rules regarding service, how much you can win, etc.
Most states waive sovereign immunity for contract claims involving the state or state entities.
FSU's lawsuit against the ACC is based on violations of state law, not federal, so the venue should be in Florida. the ACC's arguments that FSU consented to be sued anywhere probably don't hold water because even if they did, the lawsuit is about a breach of Florida's laws, not north carolinas.