All about owning snails and breeding them?

In science cl we did an experiment our our clroom pets which are snails. Our teacher told us snails are both male and female so when they mate they swap sperm and lay their eggs. Today the next generation of our clroom pets were born and my mom had already agreed to let me buy some snails (and breed them) so where do you think I can get them. NO I AM NOT GETTING SNAILS FROM THE BEACH. I am going to get snails that are about the size of hermit so can anyone tell me where you would get them? In what pet store? Also, they will be living in an aquirium tank (non-aquatic) and will eat celery ad carrots (I'm getting the diet from the cl pets so PLEASE recommend something!) Of course I was the snails to live comfortably so please recommend anything that seems wrong. Thanks! And please add a link or your experiences with snail behaivor, habitat, diet, ect. ect.