Try volunteering, there are so many charities in need of help, Citizen Advice, village hall committees, Age Concern, Woodland Trust, there is so much choice. Our Council has a central body dealing with volunteering that has masses of information. It is a wonderful way to meet like-minded people.
I was listening to Dr Mosley on the radio yesterday who was advocating learning new skills to keep your mind working, He suggested trying three new things: physical, mental and creative. I do a Duolingo stint in Dutch every day, I am not very good but I now really enjoy it, the satisfaction when I get 100% for an exercise! I garden most days when my back allows and belong to a writing group so am doing my best to keep my brain cells functioning and am never bored.