How do I file a slander suit/retaining order?

I was seeing a few girls at the same time but didn't tell the other girls. One found out and now is sending me text messages that I m a pervert and calling my ex-girlfriends asking if I ever had weird behavior in front of her kids. Making me out to sound like a pedaphile. I only had in front of one girls 5 year but he was sleeping in the room He didn't know what was happening. Im going to file a slander suit against this fning bit*h and a retaining order. How do i do that?