As others have mentioned, a spinning bike will not do much for bike handling skills. If you're not in shape, it can still be a good start, as it will help your body get used to the particular muscles and motions needed to ride.

+1 on abandoned parking lots, empty bike paths, etc. Anything fairly flat with good pavement and few obstacles is helpful. I learned to rollerblade that way back in the day - way scarier than cycling!