Dwarfs are typically very shy, nocturnal creatures and their lifespan is generally only 6-8 months, sometimes longer. They can be kept pretty easily though. They don't tend to try to escape like most of the larger species. Should be kept in at least a 20 gallon, and by themself. They will eat fiddler crabs, hermit crabs, and sometimes snails.
If it's from the US eastern coast it is probably O. mercatoris, which is a large-egged species and the hatchlings can be raised. Most wild-caught female octos will lay fertile eggs.
Something to consider is that they are only active at night, in the dark, and you need a red light to view them with. Honestly they can be pretty boring unless you're just absolutely crazy about octos. Larger species are much more active.