Welcome to the forum. I am not sure what type of tortoise that is but someone will be along soon to tell you. One suggestion I need to make however, is get rid of the aquarium rocks immediately. The tortoise could swallow them and cause major health issues. You can use orchid bark or coconut coir which is safe for them. You can even use clean dirt from your yard if it doesn't have any pesticides or fertilizers in it. Once you know what type of tortoise it is check out the species specific section for a care sheet that will tell you what you need as far as enclosures, diet etc. where did you get your tortoise?
Looks like a desert tortoise to me. Agree with the above. He cannot be on aquarium gravel. Needs dirt, water and a large. Predator proof, outdoor enclosure.
Where did you get your new tortoise? Desert tortoises are not allowed out of their home states. Yours looks fairly young, but not a baby. More a "teen ager." He really needs to be set up outside. This is not a house pet. It is a wild animal and really needs to be outside.
Nice setup, Yvonne. The desert tortoise is endangered or a protected species in some states. Do you have a large backyard? If not, consider what you have and do what's best for the tortoise please.
Please don't get scared off by hearing that you're tortoise may be a protected species, endangered, or against the law to own in your state. All of this maybe true, but don't freak out just yet i'm sure there are people here that can tell you what to do. You can do some research and see what the laws are for your state. There have been several posts on here from people in your same situation. Check out the Desert tortoise care sheet for now.