Re: Things you wish you knew when you started boating
The first thing I would tell a new boater, after finally learning this over the years, is cover your boat from the elements when not in use, and do maintenance at required intervals, because I've seen so many nice boats, in poor shape because of neglecting this, I'm somewhat guilty of it myself.
That unless you have a new boat, or a used one in great shape, not like the worn bargain boats, or fixer uppers I've always had, because, if you're mechanically inclined, you're always going to be under the hood (I/O), or the cowl (outboard) to keep it running right! and it's always "Here take the wheel, I gotta check the motor, something's wrong?" hopefully you have a friend, or significant other who will do this, but I don't, no matter how many times I've asked the bride to learn how to drive the boat in case of emergency, she refuses saying I'm not ready yet!
Also, if your (my previous) wife, or kids, get disgusted with this, you have to learn how to launch, & handle the boat alone if you're trailering, if you want to go out,
Or just put it in a marina
so you can just jump in, & go whenever you're ready. I had my boats in dry rack storage for years, it would sit on a rack, then be dropped in by a giant forklift when I wanted to go out.
( By the way, I found the marina a good place of refuge, a home away from home, and getaway from the stress at home, even if I was only going to work on the boat, or let the ex think that

)
Next, winterizing, up here in the Northeast, the most important thing is to know to get all the water out of your motor before the freezing weather hits, and not to put water in your motor in the spring, until you're sure there is no more freezing weather left in the season. Also, figure on having a place to store it, and finally cover it good.
At least learn to do basic stuff by yourself, tune ups, oil changes, impeller changes, thermostats, it will make life a whole lot easier, and less expensive for you, and when looking for parts, supplies, & oil, & lube, shop around for a good price, but be sure they're marine approved. Your local NAPA auto store usually has Sierra aftermarket marine replacement parts, at a reasonable price.