Carlsbad only requires helmets. It is a pretty fun park. Kind of small on chunky but has lots of hips and ledges and super fun lines. I love it but I am also partial to it because that is where I learned to ride. There are a few others that might be worth checking out too but if you are going to be in Carlsbad that's it for that area other than lots and lots of street spots and maybe Vista park. Clairemont and San Clemente are both about 30 minutes from Carlsbad.
What dates are you gonna be there?