I can’t give out specific spots, but in winter, I have caught most of my big gills 8-10 inches in 18 to 32 ft of water, with the most common depth around 22 to 25 ft.
This would be a really tough time of the year to target walleye for the first time, you would do much better at first ice. They are also easily caught at last ice, but the season is usually over by then. Find the perch, and look for a spot where a steep break comes right up to where the perch are. Fish before sunrise or after sundown with lighted tip ups and 10 lb floro leader. Run to the flag as fast as you can, walleye are notorious bait droppers. A common mistake is to fish too deep in the dark. 12 to 18 ft is usually a good depth