RECOMMENDATIONS TO STAY AND GO OUT IN LONDON (London)

Hi, i am going to London in May, i will travel around europe but i will stay more time in London. Which are the best places to stay in London with good connections with train and underground? I am going alone but i would like to go out at night, i really like wine and beer, any recommendation? I am thinking to go to York, Cambridge, Bristol, and i am going to Edinburgh too.
I have been in London twice and i stayied in Hyde Park, is ok?

thanks!!!