We'll need to know what species and how big your baby is before we can help you. In the meantime, take a look at the stickies at the top of our enclosure section for ideas.
(And get the idea of "cage" out of you head. You want a natural-looking "habitat.")
Welcome Winona.
Have you decided on a species? Do you already have the tortoise?
The type/species will help us recommend the type of enclosure.
Also your location. Cold...Tropical...