When I was starting I bought a Rossi District; crappy board to learn on but I felt I was committed to learn how to ride since I shelled out the cash.
I'm glad I bought a board and not rented since it made me go out more and use it. The only regret I had was my choice in the board I picked, so shop around. Lots of cheap boards for sale, no need to spend too much one your just learning on. After learning to ride you can decide what kind of riding that you want to do, and buy an appropriate board.