Questions!
Are you going to drive? Take trains.? Take buses?
What are you more interested in, historical places or seeing the places your ancestors lived.? Or just the area your ancestors lived in?
What about other fascinating places, geological, ecological, archeological?
With only 2 weeks, I would say 3-4 days max in London and then pick 2 other places as bases for exploration in other areas. Perhaps Bath and Canterbury would work well.
London is a huge city, you could easily spend a month there and not get to know the place. Some of my favourite places, The Cabinet War rooms exhibit, Hampton Court, Westminster Abbey, St Paul's Cathedral especially if you remember the bird lady in Mary Poppins singing to the pigeons on the steps of St Paul's, The Tower of London, for much more than the Crown Jewels.
Last time we actually stayed in London, we stayed at a small hotel within 10 mins walking distance of Victoria train station, which meant we could walk to Buckingham palace, Westminster, the London Eye, and also take taxis, buses or the tube.
Within the south central part of England, Bath is a must, Stonehenge is great, Chichester, Canterbury is great, Dover castle and WW2 exhibits. If you like caves, Cheddar Gorge and Wooky Hole not far from Bath.
This is a great website for looking at photos of villages and scenery, it also has lists of historic places, attractions etc. It isn't a booking and planning site, it will give you lots of ideas.
https://www.picturesofengland.com/