The only club on the beach is Huracan, and that's free to enter. If you mean resort, you can get day passes and Vista Sol and probably Sunscape (the newest one). Both are smaller resorts in Los Corales (adjacent to Cortecito).
A little farther drive is Jellyfish, Langosta Roja, and Poseidon, all also on the beach, and with access roads that take you pretty much to the shore. About 40 minutes away is Pearl Beach Club, but I don't know if they have a weekly membership deal.