You also need to make sure you have enough revenue to set up and operate the rink. You should have some extra funds too should it take a while for the skating rink to become popular.
Take preemptive legal measures. Skating can be a dangerous activity for novices, and in our highly litigious society, I'd get the legal aspect covered. Talk to a lawyer that specializes in torts, and especially negligence. If possible, reach out to other skating rinks to get some advice.