I did this at 40+ - seems a long time ago now!
For destinations, have a look at your local tea shops/cafes/farm shops etc. - there should be a few within a short distance I would hope. What I did then was to pick routes to/from them - so my favourite (Rubery to Earlswood) allows me a 20 mile round trip, extending to 25, 30 etc. just by riding in circles when I get past the hilly bit! But I didn't start doing that until I'd had some practice when I started.
What practice? Well, don't laugh but ...
Up and down the garden path without falling off.
Then round the block which initially took - well, a long time. About a mile in 10 minutes or so nearly killed me. Each night! ('cos it was dark in the evenings I didn't get seen by the neighbours!
Then after a couple of weeks twice around the block.
Then after a couple of weeks around a bigger circle.
And so on ...
After a bit I found a local cycling club which did "snail" rides, so I joined these. After a few of these nearly killing myself with exhaustion I got the hang of it - but after 20+ years I still don't do the faster rides, "rambling" is good enough for me!
Now there are local (or within driving distance) groups organising family rides and the like - I'm sure there must be something similar where you live. Though if you live near Solihull, you've got it made!
The other thing of course is to cycle to your local papershop to get a newspaper - call it an "exercise opportunity"