You visited Wedgehurst earlier, to escort Leon back home, but you didn't have a chance to actually look around town. Let's fix that! From the entrance, the building directly ahead with a reddish-brown roof and steeple is the town's train station. You can go inside, if you'd like, although there isn't much to do as trains are currently delayed because of an inspection.
Head right from the train station. There will be a path going up, with a couple of the Champion's fans standing in the way (but not actually blocking the path). Unless you're curious, ignore this path for now and carry on right. Opposite the train station, on the right, there's a red-brick house that you can enter. Further right is the Pokémon Research Lab, where Leon is waiting outside.
Approach Leon and he'll usher you inside the lab. There, you'll become acquainted with Sonia, the Professor's assistant and granddaughter. She'll add the Pokédex to your Rotom Phone. Now you can access the Pokédex from the main menu.
If you've never used a Pokédex before, this high-tech piece of kit automatically records information on Pokémon you encounter in battle. Pokémon you've yet to catch will have an incomplete page, while Pokémon you've caught will receive a full page, including a blurb describing their characteristics.
Depending on your current progress, the Pokédex splash screen may suggest recommended Pokémon for you to catch, usually found in the most recent area you visited. Otherwise, if there's a Pokémon you've seen before, you can press the X button on their page to learn where to encounter them in the wild.
That's part one of the preparations complete, but according to Sonia, the Pokédex actually came from her grandmother. So you should go visit her on Route 2 to give your thanks. Hey, it's a good excuse to continue exploring! When you're back in control, exit the lab when you're ready. Although you're more than welcome to look around inside. Of note, there are some interesting books up the stairs.
Outside, you'll get stopped by a man. He'll notice your Pokédex and randomly give you a Potion to help you out. Before you go elsewhere, head right from the lab. It's not obvious at first, but there's a hidden path between the trees! Go around to the end of the path to find a Rare Candy lying on the ground.
Now head left, back towards the train station. Then go up, along the path in-between the train station and the red-brick house. You should notice a familiar sight--Hop--up ahead. Get near him and he'll direct you to the nearby Pokémon Centre.
You'll find Pokémon Centres in every town and city. These are free-to-use institutions that are essential stops for every budding Pokémon trainer. If you speak to the kind-looking lady managing the central desk, she'll restore all of your Pokémon (in your team and PC boxes). There's also a PC box nearby where you can manage your Pokémon.
Meanwhile, the clerks on the right run the Poké Mart. Here, you can buy useful items like potions and Poké Balls. Some Pokémon Centres have two clerks--if so, the the right-hand side clerk will sell unique items. Finally, the bloke on the left who's running the cafe lets you rename your Pokémon, learn a forgotten move or delete a move from their move list.
Forgotten But Not Lost
Let's talk a bit more about relearning moves. Each Pokémon has a maximum of 4 moves they can know at one time. When they try to learn a 5th move, one of their existing moves must be forgotten (or you can skip learning the new move). By speaking to the cafe owner, you can relearn any moves you passed up.
It goes a bit further than that though! Any move that the Pokémon could have learned is also eligible. For example, if you caught a really high Level Pokémon, you can relearn moves that they learn at low Levels. There are also some moves only available via relearning, especially for certain evolved Pokémon.
Rest up at the Pokémon Centre if you need to, then leave the building when you're ready. Outside, go left back onto the main path. Up ahead, Hop will be waiting for you. Go there if you want, but now's a good time to continue left. Over here, there's a man selling a small selection of berries. These can be given to Pokémon to hold or used as ingredients for cooking curries.
For an extra edge in battle, you can give each of your Pokémon one item to hold onto. To do so, either open the Pokémon menu and select a Pokémon, then choose "Held Item". Or access your Bag and select an item, then choose "Give to a Pokémon". Whichever is more natural for you.
You can let Pokémon hold onto most items, but be careful as not all items will have an effect when held by a Pokémon. If you're unsure, read the item's description. Items that have an effect when a Pokémon holds it will explicitly mention this in their description.
Carry on left from the berry seller to reach the town's boutique. This is where you can buy clothes and other fashion items for your trainer. If you fancy a new look, don't be shy to head on inside! That said, fashion doesn't come cheap, although you did get some pocket money recently... Also, go around to the left side of the boutique exterior to find a Poké Doll on the floor.
Now run back to Hop, who's waiting up ahead on the main path. He'll bring up the Gym Challenge again and the fact that you need an endorsement to participate. Perhaps if you speak to the Professor, she could help your cause. We guess it can't hurt to try. Once Hop leaves the scene, follow the path as it bends around to the right. On your left, there's another red-brick house that you can visit.
After a while, you'll come across some steps leading down. Before descending the stairs, stop and check the medium-sized rock in the nearby corner. You should see a sparkle next to the rock. Inspect the sparkle to find a hidden Revive. Now go down the stairs. To the right, there's a small cobblestone bridge running across a river. Past that, you'll arrive in the next numbered route.