I just adopted this stray dog and need advice.

I just adopted this stray dog. His name Chai Boba milk tea. I don't know his age or who previously owned him and I'm not a dog person, but he's really sweet, and I want to do what I can to take care of him. He has absolutely no house training, is missing an eye, and has fleas. (I can’t afford to take him to the vet yet, but I’m saving up) I know very little about taking care of dogs, but I am very willing to learn. Any advice on how to take care of him would be very appreciated.