I've actually been thinking about this many times! If I wasn't a serious pokémon battler and rather just wanted to travel with as little problems as possible while still having pokémon I enjoy, I wouldn't always care about how strong in battle a pokémon in my team was, or what types I chose.
Can we, like, make this topic to be about any region though? Feels kind of restrictive to only ask about traveling Kanto. I'll edit the title to reflect this, but if you (Time Capsule Caper) really disagree, please message me and I'll revert it.
For Kanto, I'd probably pick:
Arcanine for transportation on land, Pidgeot for in air and Gyarados in water. Sandslash would be good to have if you need to cut or dig, Victreebel has vines and spores that can be useful, and Gengar is probably super nifty for scaring away stuff that bothers you or at least make you feel less insecure in the shadows. Since you know that your friend is part of the shadows, watching over you :3
Apart from the three transportation pokémon (something to ride, something to fly on and something that keeps you reasonably dry if you sit on top of it in water), I'd say it's much personal preference what you want to pick for the last three. One might want to have a psychic pokémon like Alakazam instead of a ghost, and maybe a rock or fighting type instead of a ground type like I chose. Some cutting power is good though, I'd say :3 And I think a grass type (or bug type like Butterfree) with spores and vines is pretty standard too. Or it should be!