No problem. If there's a male and female, they'll find a way to lay eggs no matter what you do. Mine are very persistent haha. You don't need another tank, in a community they tend to get eaten before long. Especially with first time parents. They usually ignore most other fish. They will fight each other a bit. When breeding they may chase other fish that come near, but mine have never harmed anything at all.
There are members here that have males together. They are mostly fine as far as I know. They fight more often, but problems mainly occur when there is a female in the mix too. Really try for a female though. Just look for the breeding tube and pick one with an obvious, thick tube and overall feminine appearance. If you find the tube hard to see somehow, go by those other characteristics and make an educated guess.and what happens if I get another male on accident? I think the ones at the lfs are juveniles. Not sure if I can return.