Questions about making a police report

So I let my ex come visit for the baby's first thanksgiving and he brought his 4 year old. He choked and hit me in front of the kids and I hit him back. That was on Thanksgiving day and I finally decided to make a report about it tomorrow morning. Will he be notified that I made a report even if I don't press charges? Do I have to press charges to keep the report on file? (He lives in a different county but I don't know if that matters). Will I have to go to court? I don't have any evidence so what happens if they don't believe me? Or what happens if he says I hit him first? Will they question why I waited so long to report it?