Go to Hogwarts, learn how to become animagi, figure out how that map works and fight death eaters. Oh, you don't mean those kinds of marauders. Well then, I g

Go to Hogwarts, learn how to become animagi, figure out how that map works and fight death eaters. Oh, you don't mean those kinds of marauders. Well then, I guess you'd have to use your tech skills in a way that's useful to them, or even build up your own group. Assuming tech knowledge hasn't somehow returned to the dark ages, someone who knows how to build and fix machines is going to be invaluable to one of those groups. Could be a chance to write some sort of communication app too, assuming smartphones still exist (or something much simpler, if you'll have far more outdated technology to work with). Something like Signal or Telegram seems like it'd be rather useful to work with in the event of a civilisation collapse.