First off, London is huge but fortunately the public transportation is rather easy to navigate. In my opinion, London is a great place to eat because it has so many different cultural communities. There is also a lot of shopping and sightseeing to be done so I recommend a hop on/hop off bus so you can go 100% tourist. As far as nightlife, their bars actually close pretty early and a lot of the youth are into clubbing/electronic music. That's not my personal style, but it may be yours!