Trespassed on accident, was told they weren’t pressing charges

Question

So I wandered into a place that I didn’t know was private property and the police found me as they patrol the area and it was daylight and told me i was being put on a no trespass notice for the area, but no charges were being pressed. What does this mean and what should I expect? I know I can’t go back (not that I would plan to now that I know it’s illegal) but beyond that i’m confused and a little scared as i’ve never been in trouble before. Will they mail me something or come to my house or is it just over and done unless I show up again?