We don't do much Bretzel in Frankfurt but we're big on Wurst. And Grüne Soße if it is still offered. Anything with apples tends to be good as Hessen is the apple counts. Äppler > Beer, which is a sort of cider, either sweet or sour.

As for beer, avoid the local brands. They're local for a reason. Binding nope, Henninger meh... Look for FXXXXFXXXXR (🤷‍♂️) and Brauhaus.

With that, a heartily 'Gude.' to you. That's GM.