First, a dumb question (I know, there are no stupid questions, only
stupid people): What is a cuddy cabin?

Second, I'm looking at getting a boat for next season.

I'd like to spend under 10,000 TOTAL -- including registration,
insurance, fuel, launching, etc. Which means that the practical limit
is around 8K for a used boat, with 1K to outfit it with "stuff" -- life
vests, cheap skis, etc. Or a 3K boat and a season at the marina.

I have a lot of sailing and boating experience in California, mostly in
lakes, with some costal sailing experience also.

I live near Lake Michigan, so I am thinking Deep V or modified Deep V
for a hull type. I expect to take up to seven passengers (including me)
skiing, and a smaller number on overnight coastal trips. That means a
practical minimum of about 18' I think. My tow vehicle (Durango) is
limited to 4500 lbs, so that limits me to 23' max. I want it to be
seaworthy (i.e., safe), can pull novice skiiers and tubers, and --
ideally -- be capable of cruising 70 miles across Lake Michigan to
Chicago.

I'm not interested in Bayliner. OK I'm interested, but I know better.
Sea Ray and Chris Craft seem to be popular brands I know.

How should I do this?

Third, what is the value of these online boating classes?