Speaking as a non-world-traveler...
If you like art, London/area visit the Tate Gallery; and for ancient doodads as well as art, the British Museum.
Glastonbury.
Stonehenge.
Tintagel.
On the way to Scotland (not sure I’d drive it btw, take the train) you could stop and gander at Hadrian’s Wall.
There are more castle tours in Scotland, because there are many more castles that survive up there, big heavy lookin’ things.
Loch Ness.
Arthur’s Seat.
Anyway, have fun!
Ooops, and if you do go the Stonehenge, be sure to visit Salisbury Cathedral.
When I go to England, these are my top destinations:
Old Trafford
Anfield
Goodison Park
Stamford Bridge
Emirates Stadium