hey congrats on the new betta. crowtails are beutiful fish. :D
here is a thread link to betta care
be sure to get a heater and would be best to have at least a 2.5 gallon tank.
when you feed the fish i would reccomend you get a good pellet or flake betta food as a staple for his diet that you feed him almost every day of the week. and then maybe some frozen bloodworms or brineshrimp once or twice a week. if your LFS doesnt sell frozen, then freeze dried is fine, but only a couple days a week though