Some attractions that come to mind include

• Beaches around Teignmouth
• Fly a motor-glider (Dunkeswell)
• Agatha Christie (on banks opposite Dartmouth)
• Dartmouth Steam Railway & River Tours
• Teignmouth to Dawlish Railway walk (on coast) - short - c 1 or so mile [has interactive map with accommodation but there are others if you go to Air BnB or sites for accommodation in Teignmoth]
• Plenty of Tor's to see / walk to across Dartmoor
• Riding on moor
• there are a number of sites where you can hire bikes with designated routes in beauty spots [Resrvoirs, lakes, Otter Valley)] (no doubt bikes would be nothing like yours!)
• Gardens at Heligan / Mevagissy - Cornwall
• Eden Project Cornwall
• Numerous other gardens with or without houses across the region
• Large number of beaches and of course the South West Coastal path

Some links below give an idea

• TEIGNMOUTH TO DAWLISH RAILWAY WALK - All You Need to Know BEFORE You Go (tripadvisor.co.uk)
• HE 10 BEST Devon Scenic Walking Areas (with Photos) - Tripadvisor
• 2023 Fly a Motorglider in Devon provided by Southwest Motor Gliders (tripadvisor.co.uk)
• WOOLACOMBE BEACH - All You Need to Know BEFORE You Go (tripadvisor.co.uk) [Actually interactive map with more sites on it as well eateries / places to stay)
• dartmouth steam train - Search (bing.com)
• Top 10 Devon Best Beaches | UK Beach Guide (thebeachguide.co.uk)
• The best beaches in Devon and Cornwall (thetimes.co.uk)
• 16 Best Places to Visit in Cornwall, UK (+ Map & Tips) (fullsuitcase.com) again has interactive map that can identify attraction and where they are
• Best of Cornwall, UK - FullSuitcase.com – Google My Maps [just the interactive map]
• 12 Best Things To Do in Cornwall Right Now (timeout.com)
   

As I mentioned the options are numerous so if can narrow your thoughts more on time, distance prepared to travel (getting to Minack Theatre - tip of Cornwall) prob another 4 hours from where we are) I can try to be more specific.