You won't have a problem with that, just every thursday(i think..) you have to buy Evening Standard(a newspaper) and there is a special newspaper inside, with all of the needed data and facts about parties
You can also buy such magazine( there are various types for different music styles, so u'll definitely find something that will suit yourself)
After buying you read an choose the party u want

But the best way to have fun is to meet people, like I did... And tomorrow one of them is arriving to visit me... and he's in a band, thats getting known slowly...so that's really worth it

Good luck!