Listen, I know this sounds like a good idea, but I am going to tell you straight up it is NOT A GOOD IDEA.
1. Not all mares are worthy to be bred. They could have a disease, poor conformation, you name it. For a mare to be bred, it shouldn't be just for fun or because you feel like it- there should be a specific worthy PURPOSE. For example, remember Zenyatta? She was that amazing racehorse filly that kicked all those other horses butts on the track. They bred her... why? Because she was proven- she had the show record, the health, the conformation- to be bred for a GOOD reason.
2. If you do breed, taking care of a pregger mare is NOT the same as taking care of a normal horse. They require good care and nutrition and check ups from vets
3. Taking care of a stud, or a colt, whatever you wanna buy, is just ... no. Thats not how it works. Again, a stallion has to be extraordinarily proven in order to make sure it produces quality babies, and this takes years of showing and also conformation and health....
4. It takes YEARS to learn how to properly take care of a baby, pregnant mare, and a stallion. It is not all fun and games. They are not puppies.
Get a trainer. Take lessons. Volunteer at your barn. Experience and learn before jumping into anything crazy, like what you want to do...
“We’re all in the same game, just different levels; living the same h.e.l.l, just different devils.”