I don't have too much to add, as you're getting great advice. But I would like to take away one thing: Please don't
get in the habit of "swinging wide" for turns. Unless you are driving a semi-truck
Now it is true that if you turn right just the same as you do in your car, your right/rear trailer tire will "clip" the curb (or post or whatever is there). But, the way to avoid that is to simply start your turn a bit *later* than you would in a car. In other words, "keep on driving straight ahead" for just a scoch longer, then make your turn "normally" without swinging to the left.
This way your right/rear tire will clear just fine, and you won't impinge upon traffic that is rightfully occupying other lanes. I cringe whenever I see that.
A couple of notes: If, say, you are turning into a gas station parking lot, and there is a car also in the driveway but coming out, you may not have room to turn "later." In that case, I typically either move on along to another entrance (you will find that you "scout" ahead like you are driving a chess game - that's part of trailering); or, if it's safe to do so, I pause for a second to let the other car come out and clear the driveway. Also, many times there is actually room for both of us and the long turn, since our rigs are really pretty short (think of how looooong a tractor-trailer is, and they don't even swing wide by all that much).
Also, of course this doesn't mean you can *never* swing wide, but please don't get into the habit, would be my advice. It should be the rare exception, if at all, in my opinion.
I used to drive a 40+ foot long straight vehicle. Now that
was fun on tight turns!
Practicing in a parking lot is a great idea. If you can, bring along some construction cones or something similar (maybe make something with pool noodles?). Then you can set up various tight turns and backing scenarios and really get good at them.