He's really pretty! Congrats on your new guy!
I wouldn't put a female in there with him, especially in that small of a bowl. I know one member on the forum has a male and female together, but they are really laid back and he has them in a 10g tank with tons of plants and hidey-holes for them to establish territories. He's a really experienced betta keeper as well. Trust me, he'll be fine by himself :)