I don't know where to start, that is a lot of different questions could be a very long response. I would recommend narrowing your questions down and search the site.
Safety equipment needed for kayaking
Good kayak launch spots in the LA area
Species of Fish to target in the LA area
Best fishing tackle to target these species
Rigging a kayak for fishing
I bet you can get a lot of knowledge if you go to this kayak shop
16910 Pacific coast Highway
Sunset Beach CA 92649
For $125 buck you can take a 6 hour kayak fishing class. You can't beat that! Full day of fishing with an experienced kayaker and angler
http://www.oexsunsetbeach.com/411.html