This old school Trek 800 with solid fork will probably fit you. Good quality and the price is right. Asking $115 might take an even $100.
Ride it, of course, before buying. Take it in to your LBS for a comprehensive tune up and get better commuting tires. Something smoother, better rolling, flat resistant. Buy a helmet, ulock, water bottle, and cage(s). Versatile ride to get you into commuter cycling and not a theft magnet. Upgrade the components over time as you wear them out or have the funds.
https://macon.craigslist.org/bik/5391093663.html


My LBS has these Continental Country Plus tires for $30. Great mtn bike commuting tire for the $. I have them on 2 converted mtn bike rigs.
continental bicycle Country Plus


Really cool bike but may be too small for you. Vintage German touring bike:
https://atlanta.craigslist.org/nat/bik/5332408207.html

Same seller, unique bike for your area. This one may be too large. Ride them both to see if either fits ?
https://atlanta.craigslist.org/nat/bik/5332416872.html


And, there is a lot to be said about getting the best deal you can from your local LBS. Maybe even a used bike or shop rebuild.
You have their support, expertise, etc., and you are contributing to your own local economy in an area of interest to you….