I saw an article about a 100 year old woman called Jean this morning. She started yoga classes in her 60s, and has continued. She looks full of vitality and talks enthusiastically about how it has been good for her physically, and also socially.
Physical activity of any kind is good for us mentally also. It does not have to be a competitive team sport, or hours of hard work in a gym – though it can be if that is what you enjoy and find rewarding.
Try out a few things, only do what you can do, there is no shame in starting off small, and when you know what you enjoy, go for it. Jean tried yoga, enjoyed it – and look at her now!