I haven't actually read your story, but thought I'd answer anyway, just for the crack of it.
1. What do you do for fun?
Same as the rest of the world really - cinemas, shopping, er, you can fish and do water sports on some parts of the river Thames... and go boating/get a ferry around the river too. There are museums and shit, and some pretty epic tourist attractions - the view from the London Eye is amazing.
2. What are typical stores/restaurants people go to?
Restaurants I don't know, but there are shopping centres all over London. The most upmarket street is in central London and is called Knightsbridge - home to Harrods and Harvey Nichols. They're the sort of places people go knowing full well that they won't have enough money to buy anything.
Less upmarket stores are like New Look and Primark - I personally hate them both though.
3. What's in style when it comes to fashion? (keep in mind Gerard and Frank's style as well)
I have no idea what Frank and Gerard wear in your story, having not read it. But in England girls wear floral dresses a lot, cardigans that make them look like old grannies and skin tight tan leggings. Yes, they're weird. Guys don't really have a set fashion - other than jeans wore halfway down their backsides.
4. What drugs are more easily accessible or you've heard are accessible?
Depends where you go. Weed and ecstasy are the most popular. Heroin also gets used a fair amount, but I'd imagine that's fairly typical for everywhere
5. What's the weather like around early September?
Usually still quite warm - you could happily sunbathe if you have a garden.
6. What are the locals like? (friendly, hostile, etc.)
Busy. London's always moving and people have a policy of not looking at each other where possible. Pretty much the same as every other big city.
Hope this helps!
Sx
Author's response
Thanks a ton! :)