I want to start breeding feeder guppys but really don't know how to start and what I need any advice would help. The only things I have is an old 10 gallon tank a heater and a basic hang on filter.
You have all that you need, guppies do not need any help to breed, in fact I couldn't stop mine from breeding...
But yeah about 4 females to 1 male, and keep an extra tank ready, once you have about 20 females popping em out you won't have room.