you will learn very quick, we bought our 26ft (31.2ft total) about 8 months ago and have gone on at least a trip a month. I am getting so much better at driving it and backing up. there is no real easy way to learn just be careful in the beginning don't try a small gas station or parking lot work your way up to smaller spots. you are the only one that knows your ability and want you feel ok driving, don't get something too big or you will not have any fun going on trips. if I go any bigger in the future it will be a 5th for sure. I tow with a 2009 2500 duramax, and it pulls that trailer with no problem.
also one important thing....check your weight on the trailer in CA anything with a gross weight of over 10k you need to get a non commercial class A. if you have not bought the trailer yet look at the sticker on the trailer and check the weight, if you can stay under 10k it will save you the headache of getting one. I think in the toy hauler section there is a tread on it if you need to learn more.