If you learn to use toe clips, it will introduce you to one aspect of clipless pedals: You feel more secure on your bike. You don't realize how much of the time you spend trying to keep your feet in the proper place on the pedals until you learn to ride with them secured. And if you hit a bump and have your feet come off the pedals, well, tou know how that can hurt! Also, it makes you ready for clipless because it is almost impossible to adjust toe clips so they don't hurt your feet.
Bike shoes have a very stiff sole. This allows all your pedal pushing to go directly through the sole to the pedal, instead of being wasted in deforming the shoe. It also allows you to relax the feet when pushing. Many riders who complain of foot pain and cramps on longer rides are trying to grab the pedals with their toes, monkey-like, even through the shoes. I know I struggled to train myself out of that. The combination of confidence and efficiency going clipless should add one to two mph to your average speed. Also, we who have adopted them enjoy the spectacle of the novice clipless user.