Watch the weather before you go to the lake. Postpone the trip if the weather looks marginal or worse. Listen to the weather radio while you are on the water. Get off at the first indication of storms or increasing winds. Be especially cautious of winds out of the east.
Make sure you have all the required safety equipment. Although not required, I wouldn't consider going out on Erie without a fixed VHF radio. Handhelds are good backup, but they have very limited range.
Finally, if you haven't taken a boating safety course, you definitely should do that before you go. There are many courses available, including the Power Squadron and Coast Guard Auxiliary.
My first walleye trips on Erie were in a 18' open bow.
Hope this helps