If you have not used an RV before, I would suggest renting one for maybe a week. You may find that it isn't something you enjoy as much as you expected, in which case it will have saved you a bunch of money. If you do like it, you will have a better idea of the sorts of features you want to look for or avoid
Broadly speaking, I think a motorhome is nicer and more convenient if you spend a lot of time traveling from place to place, while a trailer may be better suited if you spend awhile at any stop before moving on. Setting up and tearing down camp is quicker with the motorhome, and having ready access to the fridge and bathroom when on the road is convenient.