Pregnant Molly fish at Petco that Im getting PLEASE ANSWER QUICKLY!!

Question
Hi,
Okay today I went to Petco I saw pregnant Balloon Mollies and Pregnant Mollies and little tiny babies. Recently I've taken a liking to breeding fish especially live-bearers, so when I saw this "breeding" tank I really wanted to get them. The thing is I'm kinnda young meaning I can't drive. I do have a tank with another Molly (Female) but my brother which is where the tank is and he doesn't want more fish so they would have to get moved. My mom says I can have them but I have to move the tank. That's not the problem though, the problem is, is that I have very little experience with breeding fish.
Could you give me some advice?

Answer
Emma,   This is the thing with breeding fish...you are going to end up with many fish and many tanks. If you want to add fish even other Mollies' stick with the same sex. Males have one long fin in the middle on the bottom this is called a gonopodium. The females under them have two fanned out fins. You don't want to end up with a tank full of Mollies'. Though I want to let you know even sexed they can hold the milt or sperm for a few months so there is no guarantee that the new one won't drop some fry later. : ) You could also add different kinds of fish if you wanted. Stick with the non-aggressive's. I hope this helped. Good Luck, Tina