Going ahead to willy platz, you will reach into market and you can eat some prominent dishes of germany there.
Just outside that market is riverfront. That is a place one must go and sit. I sat there for about 1 hour and it was so soothing.
Check the time, If its around 4 Pm, then head towards Konstablerwache. It is a central shopping bay where you will find all sorts of brands for clothing, shoes, electronics and also famous food joints.
You can enjoy there till evening. In the night go to street clubs or sit in a open road bar to relax.
This is how Frankfurt makes you feel chanted.