Can you learn to play acoustic style guitar on a classical guitar?
To some extent yes, but you will be limited to playing fingerstyle (since you don't use a pick on a classical guitar). This is a serious limitation. A good beginners' steel string acoustic guitar (like the Yamaha FS800) is only around $200. I recommend you take the plunge and get one. Good luck and don't forget to get lessons!
You learn to play on a guitar. It is like learning to drive on a stick then change to an automatic,