Kirry is your best bet.
Not a lot of natural stuff in or around that area, bit boggy and tusocky.
If there was given the rain this week it will be even wetter than normal 😥
As above re road riding just get a map out and tour. There is the Sustrans route, 10 or 7?
nearest club
Kirry
Give Clair/Sam or Mark a call they may know a "local" who could show you some cheeky stuff
The Glentrool loop is pretty natural but is all forest road. If you enjoy taking in the scenery this is a good long loop. We start at Heartbreak Hill on the Kirry black loop, saves the long trip round to the start and means the cafe is mid ride. Climb Heartbreak Hill and turn right instead of left for Talnoutry
Some people hike a bike up onto Merrick and then bike back. Beware the weather tho 💡
Not done it for years but there is some riding around Clatteringshaws Dam area and Gatehouse of Fleet viaduct. Would need to get the map out tho, lots of forest road. All done years ago when I first started, just had to tick boxes and go on expeditions in them days.
biking in D&G