On Time Travel
I read and watched a good deal of scifi growing up. Isaac Asimov. A Canticle for Leibowitz. Doctor Who (Tom Baker, of course.) So I am quite familiar with the problems with time travel. You go back in time, right some wrong, and before you know it you’ve messed up the future entirely. Therefore, if given the ability to time travel, be careful of aspirations to kill Hitler.
Better to choose a place and time where your presence blends in. Where you can experience something magnificent without shredded the space-time continuum, as they say.
So, I would choose a Clash show in London 1978, or maybe a Clash show in Boston’s Orpheum in 1982. Both dates are on their album From Here to Eternity: Live. To be there, hearing the music and the crowd, that would be a good, safe way to use a one-time, time-travel ticket.