As you continue north from Hop's house, you'll arrive at the first numbered route in the Galar region: the appropriately named "Route 1". In general, routes are pathways that link together different towns. This one, being the very first route, is pretty simple--all you have to do is go straight north to reach the next town. But other routes can be longer and have more twists and turns.
Another thing: routes are typically populated by wild Pokémon, usually found in the tall grass, as well as other Pokémon trainers like yourself--many of who are all too eager to participate in Pokémon battles. However, because you lack Pokémon of your own, you cannot engage any wild Pokémon right now, let alone any Pokémon trainers. It won't be long before you can though!
For now, make your way north, past Hop who's standing around making sure you're not silly enough to wander into the tall grass. As you approach the next town, Wedgehurst, you should notice a gathering of people by the entrance. You can probably guess that these are fans of Leon waiting outside the train station to welcome their hero. Which means you've come to the right place.
When you step foot in Wedgehurst, go over to the crowd that's gathered in front. It turns out Leon has just arrived. After indulging his fans for a bit, Leon eventually notices you and Hop and comes over to your side. The three of you will then head back together to Hop's house.