Hello, and welcome to the site! Quite a few of us around here that fish in Germantown and Collierville. This post makes mention of nearly all the public ponds in the area:
Neshoba Park in Germantown is off Wolf River Blvd, close to Germantown Road, years ago there was a WalMart near there, most locals refer to it as the "WalMart" pond for that reason. Grove Park is near Houston Middle school, back in a neighborhood, but easily visible on Google Maps. The Collierville City Hall is right next to Halle park which also has a nice pond there.
The fish in my avatar picture was caught at Grove Park, just to give you an idea of the fish there. Look up the member Road Warrior, he's the master of this area!