Welcome to TE!

The suggestions above are pretty good. A Trek 7.1 (fx or not) or equivalent might very well suit your needs as a beginner. I suggest that you find a real bike shop (a shop that only sells bikes... not a general sports store or a department store) and ask for help. Find a place that's taking you seriously and making you feel comfortable. (Maybe folks from Chicago can recommend places?) Even in the entry-level range there are big differences between bikes: some put your more upright, others in a more "aggressive" sport-y position. Try a few, you'll see for yourself.

Please stick around, we're looking forward to your riding stories.