How much of a baby is he? How many inches is his shell?
- Big tank. The bigger it is, the less you'll have to clean it.
- High powered filter. I used a submersible fluval power filter since the water was only kept half way. Even with a filter, be prepared to replace the sponges very often and you'll have to do some scrubbing of the sides and water changes very frequently as well. I had a smaller one in a 20 gallon long and weekly would drain it in the bathtub and scrub it down.
- Spots to get dry. You can get various clip on or floating basking platforms, or partition a dry area with a ramp. There are also special made tubs with dry spots built in.
- Food - more protein when they're little, more greens when they're older. I fed mine a staple of Hikari pellets. Feed him in a separate small tub. Uneaten food does horrors to the filtration
- UVB light
- Basking lamp
- Water heater
I probably missed some things and for specific temps and whatnot I'd google some caresheets. It's been a few years...
They can be messy, but they are wonderful animals. I had one all my childhood. Once they get past being a people-shy baby, they're pretty extroverted. They will beg 24/7 for food. You walk into a room, they follow you across the tank and flail. One tip I've learned though is always watch them closely when they are on any raised surface out of the tank. Mine would always run straight off tables and beds with no regard for heights whatsoever.