There's no surfing right in Cabo. The ocean there is very dangerous, most beaches are not even swimmable. Not positive, I think you'd need to go up to Todos Santos for that (about 1 hour north)?

There's not a lot of Cabo folks on this forum. You might want to check over at Trip Advisor. There's a very active and Cabo-knowledgeable group of people there.

The prime surfing beach in the Cabo area is at Costa Azul, closer to San Jose del Cabo. As Suze suggested, check the trip advisor forums for recs.

Oh so not north up the coast, rather east?

I know I saw various activities/tour companies (or their vans) at Medano Beach in town, advertising various options. So if you don't figure it out in advance, I'm sure you can find something once you're there.

http://www.loscabosguide.com/surf/index.html

Much of the surf in and around Cabo is for experienced surfers. But there are some areas that are good for intermediate & beginners. I would check with a local surf/dive shop in the area for the best spots and what surf conditions you would find.

I meant to also add that suze is right - many of the beaches are not safe to swim or surf. Todos Santos is probably the safest and most popular with surfers but is a bit of a drive out of town.