When I was much younger, and hadn't been riding much for a few years, I got caught by a shop ride. It was fun to hang with them for a while, and then I started going to the shop for the start. The first time I did that, I got dropped after a couple of miles. They would typically do 50 mile rides in almost exactly 2 hours. When I finally managed to stay up, it turned out that just about everyone got dropped at some point. I remember one ride where there were 2 of us at the end.
Nowadays, most clubs have rides grouped by ability. I would try to find rides like that. The lowest level rides are usually "no drop."