My dog hasn't ate any food for two days, but will eat a treat. He seems like he's sad. Not sure what to do.

Sweeten up his food with some table scraps if he eats people food.

How old is the dog? This is common with senior dogs, time to switch food to entice them to eat. If the dog is not a senior, but drinking water, peeing pooping and acting normal I would wait 3 days , I've seen dogs fast for a couple of days then eat normal again. If they go 3 days with out food, then I would definitely consult a vet.

He is just being spoiled,,,if he eats treats he won't eat food,,,,we give 2 treats a day the rest is dog food and table meats

Call the vet and make an appointment. I would call now as they are open 24/7.

I can't help you with this, you may need to try something else, if he's drinking water, using the potty, acting normally. Not eating a few days isn't too bad. My dog did it all the time. If it lasts too long, you may need to take him to the vet.