My suggestion is that you look for paid or unpaid crewing opportunities available here
Offshore Passage Opportunities: Halesite, New York
3-4 weeks at sea on a sailboat and you will be well up the curve.
when you buy your boat, you'll do yourself a big favor if you buy a "needs nothing" boat, especially as a first time buyer. otherwise you are likely to have many expensive learning opportunities (as opposed to just a few). Go smaller if your budget requires, versus buying a bigger 'fix-er-upper".