Vacation fishing suggestions for this weekend

We will be staying on the Sandusky Bay side of Marblehead from Friday until Monday. I will have my 6 year old grandson with me and he loves to fish, but will lose interest if not catching something. I am bringing our pontoon (try not to laugh) so I know this will limit my options. I would obviously like to catch either Walleye or Perch if possible, but will settle for anything to keep the grandson happy. In looking at the forecast, I may be able to venture out on the big water possibly on Sunday as it looks now, but don't want to get too ambitious. Any recommendations would be appreciated. Thanks