I would start with a betta from a pet store for now, incase you mess up and he gets sick and dies for some reason. That way you could gain some experience. That way if you bought a betta from over the internet or a breeder or something (like the yellow delta you were talking about) You wouldn't have wasted maybe fifteen or twently dollars for nothing. (I don't mean to discourage you, but that does happen from time to time.)
I would give you names, but it's hard to name a betta if you don't have one lol ;)