You’ll have a great time! I love it there. Last month I saw Absolute Hell (twice) at the National Theatre, Chess and Moderate Soprano. My favorite areas are Soho, Chinatown and Covent Garden for rambling.
DO NOT MISS Borough Market for fascinating food booths - an experience I’m sorry I waited this long to see. Portobello Road on Saturday for antiques and street food if you can stand the hordes of tourists..
Besides the British Museum, see the Victoria and Albert Museum and Natural History Museum next door. Tate Modern right by the Thames and the Globe Theatre for modern art and spectacular views, Greenwich is gorgeous for a Thameside stroll - I hadn’t visited there before this last trip.
Get your Oyster Card and have a great time!
(My friends swear by visiting Hamstead Heath and Primrose Hill there for views of London but I can’t seem to get past the West End!)
Seconded! I used to work in an office right next to Borough Market in the early 2000s. Lunchtimes were a fantastic adventure, just wandering around and sampling things before deciding what to eat.