If you can afford it, go on a charter once and pay attention to what they do.
There is a gander mountain in Sheffield that has a couple seminars a year for walleye fishing. Maybe try to find something like that. There are tons of things to know and learn. Here are a few. 1.5 to 2 mph, I have found that crawler harnesses work just about all year. Allways try multiple colors and depths. I usually change colors or lures every 1/2 hour or so. I use jets and dipseys. I run the jets straight back and the dipseys out to the side(I don't have boards). Good luck