Travelling to the past includes all kinds of hazards, not least of which is ensuring that you have enough—and the right kind of—cash.
You can’t just take coins from your wallet: they’re probably dated after the year you’re travelling to. Banknotes have serial numbers, so there’s the risk of a note meeting itself. Forget buying cash from a dealer: well-preserved money can cost a mint!
Instead, we recommend that you simply rob a bank once you reach your destination year.
Consider this a friendly, local pub. Make yourself at home, bring your friends, have a good time! Meet new people, have a laugh, enjoy the ambience, and the Oxford commas.