I'd say ride at Pismo for sure. The waves don't look too big this weekend. Actually at Pismo you ride right off the beach, while at O-side you have to ride for a ways to get to the ride spot, so Pismo may be better for a first timer.
As mentioned be smart. Start in the small white water near the beach. Start small and work your way up. Don't let go of the ski, it's your flotation, and your ride to get you out of danger areas. The danger area is where the waves are breaking.
I think there was a thread on here for first time ocean riding but I can't find it.
I first rode surf on a bone stock 550 in 1990 or so. All you really need is a reliable ski and a life vest. We'd go ride in a lake after the ocean, that was our flush.
The first thing you'll want is a flush kit installed. Unless you can ride fresh water after. Either way your going to want to wash the whole thing down, engine and all to get the salt off after your are done for the weekend.
You could ride without a wetsuit, gloves, and shoes, but you wouldn't want to for more than a few minutes. I use wrestling shoes with neoprene socks. I just added a neoprene beanie to wear under my helmet.
I use a lacrosse helmet, it's got a great faceguard, and the lining doesn't absorb water. BMX full face helmets are good too. You want face protection for when you pitch forward and smack the pole.
A bilge is good insurance if your boat gets dunked, but not an absolute necessity if you are riding conservatively and don't crash and lose your boat in the breaking waves or submerge it.