>>40408466This is part of the story.
A Wooloo gets into the train station, making a mess of it. You can’t board the train while the transportation department handles the Wooloo.
You have your starter at this point and have battled Hop once. After this point, you battle Hop a second time and have a chance encounter with the legendary Pokémon of your game before it flees.
Once those things happen, you get an endorsement from Leon and are told about the Wild Area by the professor and Sonia, who want you to check it out and report on Pokémon Dens. Once you have that mission, the train system opens up and will drop you off at the Wild Area.