OP, you grew up in the incredible wide-open spaces. The Southeast is not like that. Many back-roads actually follow Indian-trading-paths or deer paths.
Riding on the sidewalk, above a particular age, is unlawful in most states. Also, do a little research, scouting about on the big interweb, and you'll find that you are more likely to have an accident while riding on a sidewalk than while riding on the road. Cars expect "traffic" on sidewalks to moving at 3 to 5 mph; bicycles will be moving at 10 to 15 mph; the difference can be traumatic ... to the bike rider.
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To previous post: get out of the city and onto the country roads for "exercise" or recreation cycling. As for utility cycling ... without knowing any facts ... I cannot comment.