It depends... if you took some solid sailing courses, you could probably get there in a few months. But you really need to learn a lot to go cruising effectively—fiberglass skills, mechanical skills, plumbing skills, etc., are all really necessary to have to go long-term cruising. The better you know the boat and the more you can repair on it, the better off you'll be.
Is this really true Dog? Some basic handyman skills yeah....but fiberglass? I think all this really depends on how much money one can throw at stuff that breaks.
If you have very little money...then yeah...you're going to have to fix anything and everything that breaks. But if you've got a few bucks...then I think you can probably cruise around for quite a while without knowing how to lay up a keel sump and survive it just fine.
Should someone know as much as possible before heading out? Sure. Can one "cruise effectively" without being all that? Sure.
Hey ut, welcome to SN dude. It's a great place with a lot of opinions! Pick and choose among them...but whatever you do...sail!