Snails have feelings. They have long mating rituals/dances where they wave their optical antennae at each other for hours on end, and then being hermaphrodites they join together their sexual organs (it looks pretty weird, I used to breed snails) and once they are done one snails chews off the other snail's penis and it becomes pregnant.
When ready, the snail will dig a hole in the mud with its tail and lay a large amount of tiny eggs. These eggs will hatch and tiny, albino looking snails will emerge (they have not yet gained pigmentation)
As for snail diet, as any gardener will know snails love to eat fruit and veg. The snails I used to have seemed very fond of cucumber, but I would try to give them a variety of foods. Only give them a small amount though, as snails, depending on their size of course, don't eat much and you will likely have to remove rotten food from their enclosure as they wont finish it in time.
I was breeding general garden snails of the yellow and brown variety. I have always wanted to own a giant african land snail but have not gotten around to that yet.