You're on the right track with fishing the chain of lakes in Minneapolis. There are a ton of options available to you. Don't overlook fishing the Mississippi River, or any other lake in that area. You have hundreds of possibilities.
What type of rod setup do you have right now? Any specific species you're looking to target?
It's a good time of year to be a fly fisherman in warm water fisheries. Right now, fish are starting to put the feedbag on in shallow waters. The opportunities are there to catch walleye, pike, bass, and muskie if you're geared up for that. Also, pay attention when you're walking those shorelines for feeding carp. Carp are a lot of fun to catch, and will definitely help you hone your new fishing skill.
Also, if you're looking for nearby lakes, and public launch information check out the DNR lake finder. http://www.dnr.state.mn.us/lakefind/index.html