Hi Maria:
I would suggest that after renting an RV, you spend your first night(s) at a campground near home if possible. This would give you time to practice the day to day operations of an RV (like learning how to dump), hookups, etc. before heading out on a long trip.
Some RV rental companies will offer a "rent to own" deal, such that your rental fees go towards the purchase. If new to RVing, I think you should decline this offer unless you really know the kind of RV you want and can afford.
The largest RV show in the US is claimed to be at Hershey PA in September. Even if you are not yet ready to purchase, it provides a great opportunity to compare and contrast various models. We went several times before buying.
After your maiden trip, if you feel the RV lifestyle is for you, do some research to develop the specs. you would like in an RV. If you are still considering full-timing at that point, the Occupant and Cargo Carrying Capacity of the RV is probably the most important factor to consider. What floor plan, what kind of roof, what kind of outer skin, how big should the holding tanks be, etc. Consider a RV show to help with this.
Best wishes,
Bob