I used to live and work in the city and loved telling people about the dragons guarding the city borders and the often weird and funny traditions. As much as the city is a hub of corporations it's actually far from the soulless place many make it out to be, and there is lots of interesting history there if you care to look. My favorite gateway drugs to learning more about the city of London are probably CGP Grey's videos:

The (Secret) City of London: History Edition: https://m.youtube.com/watch?v=LrObZ_HZZUc

The (Secret) City of London: Government Edition: https://m.youtube.com/watch?v=z1ROpIKZe-c