If you're looking for a meeting place or a good stop around ½ or halfway between Atlanta and Macon, you can try Towaliga, GA, which is about half an hour southeast of Atlanta, or about half an hour northwest of Macon.
Another possible place to stop near the midpoint is Weldons Crossroads.
About ¼ or a fourth of the way, you can stop at Stockbridge, GA. This is about 18 minutes southeast of Atlanta.
About ⅓ or a third of the way, you can stop at Flippen, GA. This is about half an hour southeast of Atlanta.
About ⅔ or two thirds of the way, you can stop at Higgins Mill, GA. This is almost an hour southeast of Atlanta, or about half an hour northwest of Macon.
About ¾ or three fourths of the way, you can stop at Star Mills, GA. This is almost an hour southeast of Atlanta, or about half an hour northwest of Macon.
If you drive straight through without stopping at all, the total distance is 84 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 1 hour, 16 minutes.