How to do with guppies?

go to your local pet store their bound to have them and if they don't ask them where you are able to purchase them

They won't fight, they will try to avoid the males sometimes because the males constantly follow the female. They will fight if they want to. Males don't constanly follow the females. I have seen my...

Usually, yes.

Yes they can and do. That is why smart people with fancy guppies do not allow the plainer ones in with the fancies. The fancies will not associate themselves with the reggos.

That does not happen with guppies. They stay the same sex for life.