The docks at Cathedral are posted "No Fishing", so I wouldn't advise fishing from them. Seems silly, but that's the rule. Not a lot of great bank access right there.
As far as resident species - you're looking at bass, carp, catfish, sturgeon, and panfish mostly.
Typical techniques used for the various species should work just fine there. For bass, toss crank baits, soft plastics, or spinner baits around the structure and cover within casting distance, and there's quite a bunch of it around there. For carp, catfish, and sturgeon - bait fished on a three-way set up or sliding sinker setup will work. I'd opt for a heavy, abrasion resistant main line (braid would be my first choice) with a lighter mono leader. Hard to go wrong with crappie or perch fillets for cats and sturgeon. Bread balls, corn, or dough balls for carp. Or make boilies (ask Drew for a recipe)