Get a used RV in order to minimize the amount of money you will lose. Notice I said minimize - an RV is a depreciating asset like a car.
Go with quality. If you have to go older to afford quality, do it.
I would recommend you go with a class A or C with at least one slide. Get all maintenance records - make sure it was well cared for. Maker sure it has levelers you can use while inside the coach.
Blue Ox makes a lighter tow bar that is easier to lift.
If you can find someone that has a coach, have them show you the process of hooking up a car. But you will need a car that can be flat towed - there are lists on the FMCA site. The car you have may need to be replaced in order to flat tow.
Go to the class A forum and read threads about how to select a coach.