The Ramblers are pretty active and well organised in Cornwall Milly. When I came back to walking a few years ago I too needed a bit of company, to spur me on occasionally. As I recall I first used the ramblers web site to get ideas for walks. All the walks are graded so you can pick walks that fit your location and ability.
https://www.ramblers.org.uk/go-walking/find-a-walk-or-route.aspx# Then, once I had an idea of what I could manage, I simply joined a few group walks on spec. They were all freindly and encouraging from the off. After a few walks I decided I enjoyed it and joined officially. I also tried 3 or 4 different local groups, before settling into the moorland group, where In have now been a member for 3 years.
Typical groups have around 50_100 members and on a wet windy winter walks maybe only four or five will brave it. But on a sunny still summers day we had 36 turn up. So lots of new freinds to chat with. Me I prefer four or five.