Bored in London - fun solo weekend plans?

helloooo, I'm looking for something fun/ different to do in london this weekend.

my sister has gone travelling for 2 weeks (she'll probably see this - hello!) and we usually hang out. now I'm looking for things to do... I feel like I've done all the museums/ art galleries and kind of bored of them now.

also considering a day trip from London - happy to travel like an hour/ hour and a half out. any inspiration?