What ever your friend does, tell him to take it slow and ride within his abilities.
I was 55 and had not rode a bike in 30+ years, and had never drove a big bike.
BUT, with the kids grown, me and the wife wanted to branch out so we bought an Electra Glide.
I took the required riders safety course and started practicing in a deserted part of the parking lot at the local mall.
After a couple weeks I ventured out onto local back roads, another week or so I hit the 4 lanes around our town. Another week and my wife was a passenger and we started venturing up and down A-1-A on the weekends.
We started riding with local groups, on weekends we started riding to The Key's, up to Titusville to the National Seashore, a weekend trip to the Ocala National Forest.
This summer we trailered our bike to The Smokey National Park and did day trips in the park, on the Blue Ridge Parkway and even a trip on the Tail of the Dragon.
In the last 2 years we've had our share of CLOSE CALLS, we live in South Florida, so trying top steer clear of cagers is a full time job, BUT I make sure I drive within my means and make sure I am a defensive driver at all times.
Good luck to your friend.