I’ve lived in Charlotte for the past 5 years. Love it here! Cycling is good and growing. There are some greenways, but not really well developed yet. Local gov is working at it though. If you are interested in group rides, there are several to choose from. Mojo has been mentioned - they do 40 - 50 mile rides at a fast pace. And you are on your own. Routes are well marked on the road. The meet in Matthews. I ride with a group that meets at Ultimate cycles. Avg about 17 mph. Both rides go on back roads. There are more rides, but I am more familiar with these two.
Hope this helps.