Anyone know of a group that does free walking tours of Rome? TIA
Why not just use Rick's "Heart of Rome" audio tour?
https://www.ricksteves.com/watch-read-listen/audio/audio-tours/italy
http://podcasts.ricksteves.com/pdfs/heart-of-rome-walk-map.pdf
Additionally, we've used any number of self-guided tours provided in various guidebooks. A nice thing about doing it on your own is the ability to go at your own speed and take breaks as needed/desired.