A Pokémon of your own, of course! That's the only way to do it - if you're a rookie Trainer, you'll have at least one partner to call on. If you don't have one, you're better off taking a train or calling a flying taxi to get where you need to go.

[ thankfully, Galar's public transit system is sprawling and convenient! even Raihan himself likes taking the flying taxi every so often - Flygon can get the job done, but there's a certain luxury of letting a cabbie and their Corviknight do the driving. ]