If you want to grow oysters you can you use a method called PF tek, which is normally used for psychedelic cubensis mushrooms, but also works very well for oysters. You can find detailed info on the process and method on shroomery, where you can also find many more methods for edible, non-psychedellic mushrooms.
Basically, you'll need a pressure cooker and a bunch of wide mouth Mason jars, plus a substrate (a growth medium), which for oysters can be coffee grounds, hay, or, for the PF cake method, brown rice flour and vermiculite..
Good luck