[JasonCSU]

I don't know about all of Europe, but free WiFi was hard to come by when I was traveling in Germany and the UK. Pretty much all the WiFi networks required some sort of payment to access them. I would suggest adding a global data plan to your phone for the month while you are traveling, but since you are using Verizon, that is not an option.

There is so much to see and do in London that I would highly recommend bringing a comfortable pair of shoes because you will probably end up walking more than you think. Also make use of the Underground for getting around easier. The best way to pay for use on the Underground is with an Oyster card. It allows you to add funds to the card, then you just scan it each time you enter/exit a station instead of buying individual tickets. You can always add additional funds to it if need be.

Here are some of the things I'd recommend seeing around London:

Imperial War Museum - very impressive with all sorts of things on display.
British Museum - what don't they have here?
London Eye - every tourist should check it out at least once.
National Portrait Gallery - free admission and all sorts of historical artwork on display.
Tate Modern - free admission and lots of exhibits.
Covent Garden - always seemed to be some sort of live entertainment going on.