This isn’t a social version, but if you wanted to get started with Yoga I really like the youtube channel: Yoga With Adriene. Has a lot of beginner playlists and focuses on getting the movements and poses correct.

Also possibly look into yoga classes meant for older folks. They tend to be more chill from the few I attended with my in-laws.

Yoga is a interesting option for mobility!

How much of a hassle is moving the treadmill in and out? When your using it, can you actually get work done, or more passive activities?