The club I belong to has over 155 members some of these may not even still own a bike, do not get too hung up on organised rides or how fast, somewhere in that club will be members who will ride your distance at your speed, they will also be called your new friends.
Organised club runs tend to be anything from the wrinkly ride at 14mph where you will come across some members aged over 80 in our club, these rides may be 30 or 40 miles and nobody get dropped. The there may be a more sporting 16 mph group and a faster 18mph+ group.
Join a club and organise your own rides, you will find that other members will be happy to join in with you.
Ask not what your club can do for you but what you can do for your club, this will make you a very welcome and wanted member of any cycling club I know of.