Here is a general setup for an indoor land turtle. You want to make sure that the walls are tall enough so that your turtle will not escape. They are great climbers! Be careful what you set by the walls.
The basic necessities are to have: a food dish, a water dish, a full spectrum light, a heat lamp, some substrate or newspaper to bury in, and a place for your turtle to hide. Sometimes they feel stressed and need to hide from the world.
If you have multiple turtles in the same home, make sure that you have a hiding place for each. It’s very important that you keep a shallow water dish, not a deep one. Land turtles are not good swimmers.
They may drown if they are in too deep of water. I have drawn in a pretty simple looking ladder. Although they are great climbers you should have a way for them to enter and exit the water. That way they do not flip over on their backs in the water and drown.