Help with ordering inventory for first time?

Starting my clothing line. I'm ordering about 15 pieces of each style. How many styles should I start off with? Should I be spending hundreds, or even thousands on inventory to start? I don't want to take too much of a risk cause what if they don't sell? I also don't want to have too small of a selection. If you order inventory and fulfill yourself, let me know what you did when you started out!