Welcome from just across the Mississippi River over in Belleville Illinois.
Check out the Bicycle Fun Club / Trailnet rides at trailnet.org .
STLBiking.com has rides listed; however, it's more about racing.
If you don't want hills, there's the Katy Trail. You probably don't want to take your Bianchi on it. Something with fatter tires works better plus you don't want to mess up a nice Bianchi. FYI: Your Bianchi isn't teal. It's color is Celeste. It's one of the most iconic colors in bicycling.
It's also really flat over near Portage de Sioux and Hwy 94. Wind can be a problem though.
I believe that there's a nice bike path near Sunset Park. Creve Couer Park has some good bike paths.
If you really want to get adventurous, there's a great collection of bike paths over in the Metro East. One of the best places to start is the trailhead behind the Culver's Restaurant on Hwy 157 in Collinsville. Just off Interstate 70.