What is the best way to catch big fish from a dock in wisconsin?

i am getting mad because my friend always tells me he catches 20 inch northern pikes and walleye, then when i go to go fishing i end up catching a bluegill. I use spinner baits when i try for big fish, i use red and white and a multicolored, i also try sometimes using bright colored plastic fish lures. Any tips on how i can improve, im also thinking of trying to fish off my aunts friends boat sometime but my dad tells me you can catch em off a dock too. please help!