There is a bait barge, after heading off from the boat launch it will be on your right just as the harbor curves to the left, next to the fuel station. It use to be on the left of the harbor, sorry, I never remember landmarks, I just kind of have a built in radar
Plenty of places to fish, you can through jigs up along pilings, rocks and docks. Drag some bait down the center (watch boat traffic, the channel is marked) or head out to the end and try the rocks at the end of the harbor. Lots of area. Google Marina Del Ray and you'll get a decent layout of the harbor. Good Luck.