Nice looking crab! I have lots of tips. They're fairly easy to care for, but unfortunately they DO need a specific environment unfortunately. The two most important aspects are brackish water and land access. I wouldn't recommend them in a community tank for this reason. They need to be in a specific gravity of at least 1.005 which means adding a certain amount of marine salt to the tank(most freshwater fish will not be okay with this, which is the biggest problem). They also need somewhere to climb out of the water and breath air. At minimum, some driftwood or a floating platform. Otherwise, they will slowly drown, usually within a month. Oh, and they are very good escapers so make sure you have a fully covered lid, or you might find them on the floor one day.
As for food, they will eat pretty much anything. Flakes, pellets, frozen foods, and sometimes veggies.