Hi Goldfish Bowl
The first thing you will want to do is get a few more of them and make sure they are mature. Then I'll be happy to help you right here.
When you go to buy them, if you don't trust the sales person to pick out males and females, here's how to pick them yourself. First, after you look at them to be sure they are healthy, pick the biggest ones. These will almost always be the females. Ask the clerk to let you look down on them so you can see their shape. They should be rounded. Then pick males from the tank. They will probably be much more slender than the females and possibly shorter too.
Here's a picture of my mature black corys that shows the difference well:
The chances are that the ones you buy will be much smaller and you will have to spend a few months raising them to adulthood. This is not a bad thing because, while you will have to wait for them to be ready to spawn, you will be able to raise them to be healthy and strong by feeding them a good diet and keeping the tank nice and clean.
I would suggest that you set up your empty tank and make it a single species tank for them. After they mature and spawn you can then put them in your main tank and raise the fry in it, since they will need to be alone to grow successfully.
Good luck to you with this. Bronze corys are one of the best fish to start out when you are ready to try breeding an egg laying fish. There is a lot of work involved, and it takes some time, but IMHO it's well worth the effort!
Please let me know what you are going to do.
