Alright...Where do i begin...

Ill try & make it brief. Im going to see Axl Rose's "Guns N Roses" in Dublin next Friday night. I then hope to fly from Dublin to London on the Saturday morning & see Bon Jovi and then flying back up to Scotland on the Sunday morning.
Having never been to London & it being such a large place, im a little intimidated with where to start with planning this detour at such short notice.

I beleive luton is the closest airport to the venue. But what is the best way to get to the bowl from the airport? Also, Where do i go after the gig? Im guessing any hotels near the venue will be booked. London probably has 24 cafe's of some sort, but central London seems so far away, whats my best way to central London from milton keynes bowl? My best flights are from Heathrow. Is this airport open 24 hours? If so i could just somehow get from the milton keynes bowl to heathrow & get a coffee or something!?

I know im rambling and this probably makes little or no sense, but i want to make this work & thought fellow Bon Jovi fans where the best people to turn to for help in the situation.

So any help, advice, or anything at all would be greatly appreciated,

Thanks