Do you have to buy a ticket for each cave you visit? Or can i buy one an use that for all them?

There's only one entrance to this cavern and requires a ticket led by an awesome tour guide.

There is only 1 cave at Natural Bridge. But you can buy a combo ticket for it plus the Natural Bridge itself

You can also buy a ticket for the natural bridge and the caverns , if you intend to see both of them I recommend the combo it's cheaper