He might just be trying to explore and get used to his new enclosure. Or you might have a too small enclosure. Is your tort an adult? What type of tortoise?
Could you take some pictures of the tail? I could tell you if your tort is male or female. The tortoise will need an enclosure of at LEAST 8 feet by 4 feet since he is an adult.
I hate to bring the bad news but glass tanks just aren't suitable for adult tortoises. I would recommend custom building an enclosure that is about 6 feet by 3 feet for a russian tortoise. You can look up videos on how to make a tortoise table out of wood. The pacing is most likely because the enclosure is too small. The not eating is typical but if it lasts any longer then you have a problem and you may need to see a vet.
6 by 3 is still smaller, 8 by 4 would be much better. I agree with @saleena.lewis glass tanks work for babies, but not adult Russians unless you have a 200 gallon tank or something that’s really big. Building your own tortoise table is cheaper, I would recommend doing that.