London is the greatest city in the world. OP, I hate tourists though...I would prefer u didn't come here...thanks.
TripAdvisor is a good place to check the reviews from occasional to frequent travelers. https://www.tripadvisor.com/Tourism-g186338-London_England-Vacations.html
I also want to visit London. This is one of the most popular tourist destinations, and there is no surprise. I can suggest checking a Lonely Planet London travel guide. It will provide you with some useful and helpful information.
Go as soon as you can. One of the most interesting places to visit. Big enough so that if you have a favourite interest or pass-time, you can research it and find something along those lines there.
We went with our youngest and his club soccer team. We had an organized tour of the usual sites and it was actually pretty good. I'm not a big fan of the usual tourist stuff when we travel, but this was worth it. We also went to a Chelsea v. Stoke City match. That was a fantastic experience. Everyone was wanded and security searched. The fans had separate entrances, and there was a double row of security people between the sections. People were still reaching over trying to start fights. Instead of just yelling f--- whoever or whatever, they have songs and chants all game long that are hilarious. The soccer was fantastic to watch also, especially with no play reviews every 5 minutes. So much history to see there I wish we had more time. Next trip is going to be Isle of Man for the TT races and I hope to loop back to England, or Ireland.