I'm always nervous when I hear about someone wanting a tortoise as a pet. People think they are easy animals to keep. They aren't. They are actually difficult to keep correctly. They do have a slow metabolism, which means they are slow to die if you don't take care of them correctly. Unlike a bird, which can die in a matter of hours or days if the conditions aren't correct, it may take months or years for a tortoise to die if you are clueless as to what it needs.
You can't do too much research before you get your tortoise. Especially
make sure you understand the dietary requirements of the animal you finally get. I'd say that 8 out of 10 tortoises in captivity are slowly (and painfully) being killed by their owners due to an inadequate diet. It's MUCH easier to kill a tortoise through "kindness" than starving it.
know too much about the diet!
The Russian tortoise, Testudo horsfieldi is a good one to start out with, but even they are challenging animals to keep, ...if you want to do a good job. It's easy to keep them alive for a few years. They are hardy animals, and seem to refuse to die even under the worst abuse. However, to have them thrive, you need to read up on their diet and environment. They are about the largest tortoise that can really be kept indoors. Anything larger, especially Sulcatas or Leopards, really need outdoor accommodations.
Just curious, are you aware of how long torts live? Even the smaller species, like Russians (T. horsfieldi) live upwards of a 100-150 yrs if well cared for. Assuming you are a good keeper of your new chelonian, you need to plan what you are going to do with him after you are are gone.
Here is the care sheet page from The Tortoise Trust
, they have lots of good info there and by joining you can interact with lots of dedicated people who may share your love for these guys.