How do I get into couponing and actually get what we can eat?

Our food shops here are either Walmart or Shaws. I don't even know where to get coupons anymore. I haven't done it seriously since I helped my Mother do it years ago. The coupons I have seen are mostly for prepackaged junk. That's what I don't want. Do they ever have coupons for produce or meat? We're trying to eat healthier so chips, soda and junk are big time not an option. Do I need to find a newspaper weekly or join a club or something. Please help...lol