If you want to eat near Wrigley, there's the Rockit Burger bar. Clark & Waveland. There's also 1 downtown in the loop called Rockit Bar & Grill. 22 W. Hubbard. Pub atmosphere. Pool tables upstairs & a bar upstairs as well. Great burgers & great brews. They will have craft beer & the standards. I believe I had a Founder's Porter w/my cheese burger.
Murphy's has been there forever. Waveland & Sheffield (behind center field across from park) I haven't been there in a long long time... So not sure about their food or if they have craft beers.
And of course, the Cubby Bear at Clark & Addison. But I recommend Rockit over the others near Wrigley.
Downtown, Another great spot is Howell's & Hood. Over 100+ beers. Pub food. Michigan Ave. at the Tribune Tower.
If you prefer steak... Well, it won't be cheap any where in Chicago. But Smith & Wollenski's (by House of Blues) is great. Bowling Alley at House of Blues as well, but again, pricey. So is Gibson's. Chicago Chop House. All downtown. But still just a short cab ride to or from Wrigley. Since you're looking for free showers doubt steaks are in your budgets... LoL! But just throwing it out there.
I live an hour from the city & schedules are wack during summer, so no showering at my house...