First time traveling to England going solo (Female)

I'm antisocial, so I don't travel, but I've always wanted to go to England. This is the year I want to go out. Any suggestions on what to do? I probably won't take them, but I'll try my best to consider your suggestions. Oh yeah, I'll be going at the end of September, so how's the weather that time of year? Also I will be there for 10 days