Best way to get an old gmail account back?

Yes, device and location matter more than anything else. Do it from the computer or phone you used to sign in from, on your home connection, not mobile data. Give the last password you remember even if you think it's wrong, and the month and year you made the account roughly. Don't skip questions. Then wait, Google often rejects and then passes a repeat attempt a day or two later because it weighs consistency. If there's a recovery email set, check it including spam. If you're still signed in somewhere, like an old tablet or a YouTube app on a TV, use that to add a new phone number before anything else.