Not human prehistory. That one would suck, I’m in no way built and trained as a hunter-gatherer. Either some civilisation, pre-humans or a recent era, then.

From the wording I’m assuming limited control of where I land, So I can’t airdrop in behind a world leader or into a vault, but I can choose a region.

Gilded age is tempting, for classic “change history” reasons, and because I could kickstart semiconductors early and make a buck. The disadvantage is I’d be destitute on arrival, and my education, while extensive, is undocumented there, so maybe I’d die in a coal mine anyway. Perhaps I’d pick England and try to chat up Bertrand Russel, he could vouch for my knowledge after a quick conversation and might even be a good choice to explain my situation to.

If I’m going ancient civilisation, probably Rome. I could find some sort of industry to start and even just my clothes will be valuable. The Incas would be cool to but if I’m being adventurous I want more time to prepare.

Pre-human, maybe New Zealand. I’ll eat local forage and hunt moa until I eventually die. It’s better than starving, and I don’t have to worry so much about large predators.