What to see in London

I am going to London on Saturday for a few days. It will be the first time for me visiting London. Feel free to add something if you have any advice what to see or do there!
  1. Doing a Harry Potter tour and visiting the Warner Bros. studios
    Taking a special bus and drinking Butterbeer
  2. Visiting the British library, national gallery, different museums
  3. Going to the Buckingham palace, Tower of London, House of Parliament...
  4. Meeting my cousin who is super cool and lives there
  5. Visiting Camden market
  6. Borough Market
    Suggested by   @Diplomatic_diva
  7. View from London Bridge
    Suggested by   @Diplomatic_diva
  8. Boat ride up the Thames river to Kew Gardens. http://wpsa.co.uk/content/zoom/routemap.jpg
    Suggested by   @Ahartnyc
  9. Climb on the lions at Trafalgar's Square!
    Suggested by   @amieshmamie