What a lovely story, J.! Thanks for sharing.
We carry coupons in our car, good for a free meal at a restaurant that caters to the homeless. We also smile and look people in the eye and ask "How's your day?" or something appropriate when we hand them out. Most of these folks really appreciate being treated like a real person (not all; some are too shy/ashamed/mentally ill to respond easily).
Many years ago, when I was separated from my husband and raising my daughter on a minimum-wage job as a teacher's aid, a church gave all low-income families at mt daughter's preschool a $20 check for holiday groceries. Although I was just making it, this helped so much. I've been paying it forward ever since.
If I notice a family living in a car, I'll drop off a bag of fruit, cheese, and water if possible. I chat when I can, but there's very little else I can offer on my budget. But another "free" favor I sometimes do is to help little old shoppers reach items on shelves or read labels.