I need to dumpster dive out of necessity, but I'm afraid of getting fined or arrested.

We are really struggling financially, and I would like to dumpster dive for food, house items and Christmas gifts. I have done some reading online and it is not illegal in my area to take things if public property ( like a curb, which o have done frequently) but I am not allowed to go on private property. All stores and their dumpsters are on private property. I have two young kids and I'm afraid of getting caught/ arrested. I am also afraid of a fine ( since we obviously can't afford to pay that). Am I missing something or do I have to trespass in order to dumpster dive? Have any of you had a run in with getting caught?