Andrew,
I agree with all Tom said. I've sailed and raced for 50+ years both open ocean and lakes. The only thing I would add would see if you can't get yourself a crew slot on a boat that is raced regularly. Racing is really the only way to build and improve sailing skills because you can get direct feedback on anything you do with the boat. Learning the lesson of "Velocity Made Good is far better than just velocity" separates skilled sailors from "reach and runners". It's a great sport. I hope you enjoy it!
Regards,
Tom