Growing up in rural Illinois in the 1980s meant a large number of the books I read came from places other than bookstores.
We did have a Waldenbooks in the mall that was 45 minutes away that we went to 4x/year, but the local library was tiny and I read everything worth reading there probably before I was 10.
The local grocery store had a small section of mass-market paperbacks, and it was my primary place to get books. I know it had lots of Stephen King novels, and I think my first copy of Dune may even have come from there.
(Hardcovers were something that libraries had, not anything normal people would buy, as far as I knew.)