How large is the little fishy? If they are small then it is almost impossible to sex them.
Once the are a little larger then the easiest way to sex them in body shape. The females have a wider body while the males ahve the widest part of their body at their gills and taper down from there. the males also have a rounder head, the females tend to have a bigger mouth and its bumps out a bit
Best thing to do is get a pic up so we can have a look.
Breeding them is not as easy as bristlenose. Infact i know people who have tried for years to breed them with no luck, while others have simply struck it lucky and got them going quickly. In essence they breed the same way as bristlenose but are much more picky about their water conditions etc. they also breed better in trios (1m, 2f). they take a lot longer to mature than bristlenose too. the are considered mature at about 2 years old