Hairless rat care please help?

Ok, so i got a ,male hairless rat (Otis) tuesday and he is currently living in a 10 tank. i know this isnt good proper housing in just waiting until i get the topper for his cage. but i wanted to make sure i was doing everything else right, i have a temporary water and food bowl in there for him. he gets fresh food and water every evening. I take him out AT LEAST an hour a day; sometimes i just sit in a chair with him and today i let him run around my back room as a watch and he also has an excersie ball. After my tank topper arrives which shuold be on monday im going to go buy him a male roomie so he can have a friend. but i wanted to make sure i was doing everything else right. like i said ive only had him for a few days.. is it good that he eats out of my hands sometimes? and lets me pet him while he's cleaning him self? i want him to trust me casue id never ever hurt him. Oh! i also try to feed him some fruit everyday, today i tired pears he didnt take any :/ well please let me know if yu have and tips or concerns.. also i was wondering sense ive only had him a few days how i should go about introducing him to his roomie.. im planning on getting the other one from the same litter he was from. And how old do yu think he is? he has little fuzzies on him but he's only about 3.5 inches long.. one guys at the petstore said about 6 month maybe he said weeks? but the other said about 1 month. thank you very very much!