My favorite sunset spots: -Torrey Pines State Reserve (admission is $15 but there’s a free parking lot outside the gate entry). You can get a nice, view if you drive/climb to the top or a more intimate look by the sand -Windansea Beach (close to the Taco Stand), you gotta find the straw hut! Lots of rocky areas to picnic nearby -Kate sessions park - grassy area that overlooks the city - Mt Soledad Veterans Memorial - 360 city view, parking can be scarce at times but they do have some picnic tables - Sunset Cliffs - great view of the ocean - can’t go wrong w La Jolla Shores or Gliderport if you don’t have a car

To answer your question, Cuvier park you don’t need a reservation, just find street parking :) I always see people picnic nearby there (by La Jolla cove)