What foods and fluids should i give my son with a cough?

Avoid milk: Milk can sometimes make a cough a little more productive due to its consistency. I'd give him plenty of water (or pedialyte if he's not eating).

Any food and drink: Your son can eat any food which is soft ,sweet,salty not very hot .It is important to drink more fluids as it helps to lessen the cough. Fluids can be water juice,milk

Avoid mucus prod: Fluids in general are good regardless of type HOWEVER would avoid mild products since they increase mucus production.