How can i get my recently adopted dog to start eating?

A lot of dogs don't eat when upset, or adjusting to a new environment. Good that you keep him away from garbage and the cat food. I have some experience with this. My advice would be to NOT leave food for him where he can eat at will. Decide which dog food you will feed, than put the appropriate amount for him, or a little less, into his bowl and leave him with it. Don't coax him with it, do not disturb him. He could be in a room alone with it, or in his crate (which you should have as a 'safe place' for him.) Check on him after 15 minutes; if he has not eaten it, take it away and don't offer any more food 'til the next feeding period, whether it's the next day or in about 12 hours. Always give him access to water, though. When he is hungry, he will start to eat. But stop the bribing and coaxing and checking on him when he does have access to food. Just a thought: he has no health problems, such as sores in throat or mouth, or any injuries that might make eating impossible, does he? Good luck!