When I got my Bettas, they tended to hide behind their plants for the first few weeks. Your Betta is in a new home, and just needs time to get used to it and figure out he is not in danger.
You are feeding him too much. Bettas only need to eat once a day. It's even okay to skip a day now and then. I fed mine Hikari Bio-Gold Betta pellets, 4-6 baby-sized pellets once a day.
Since you are new to Betta keeping, I urge you to go to a book store, pet store, or your local library, and get a book or 3 on Betta keeping. Then you will have everything you need to know to keep your new little friend happy and healthy.
First thing, a bowl is not ideal. He may survive, but will not thrive. A 2.5 gallon tank with filter and heater is better, and easier to keep clean. Put at least one aquarium-safe silk plant in it for him to hide behind. Imagine how exposed you would feel in a glass room!
Good luck and happy fish-keeping!
Betta owner for years.