New to the 5th Wheel life and I could use some help!

[HappyHaulin]

Soo my boyfriend and I are in the process of buying a 5th wheel right now, we're getting everything in order and planning our trip and what not, I have about a year to figure everything out. By I am very new to this and I was wondering if anyone could answer a couple of questions for me. I was wondering if there are weight restrictions or anything like that, also if it is legal to pull a fifth wheel on your truck and a car on the the back of the fifth wheel?? SO i guess length restrictions? Do you have to stop at weigh-in stations or anything? If anyone knows of any good and helpful websites I would be very greatful. We are planning on touring the country kind of, so also any suggestions on must see places let me know! I'm so excited, thank you anyone for your help!