Simple! Breed Ditto! :D
Ditto can only be found in the Pokemon Village, which you will discover much later, however you can find one over the GTS. It shouldn't be that hard.
If you can't find any decent offers, or you simply don't have Wi-Fi, then there is no way you can breed your male Braxien. Pokemon has to be so sexist to the starters. x)
Hope I helped. :)