Now that you’ve made your way to Pewter City, you’ll find your rival, Trace, waiting for you in town. He’ll come over to say hi and tell you about the Pokémon Gym in town. He’ll give you 5 Potions to help in the upcoming Gym.
In case you’re unfamiliar, Gyms in the Pokémon series aren’t the kind where you go to exercise or work out — no, in the Pokémon world, Gyms are buildings in cities where you take on the Gym Leader, or the equivalent of a boss fight in other RPGs.
Gym Leaders usually have a theme around a single type of Pokémon and also may have stronger moves and higher level Pokémon than other Trainers you’ve fought up until that point.
Upon beating a Gym Leader, you’ll earn a Gym Badge, and you need eight of them in order to take on the final challenge: the Pokémon League.
The Pokémon Center can be found near the entrance of town. Inside, a man on the left will sell you some Pewter Crunchies for 500, although you can only buy one every day. These heal any status condition the Pokémon is suffering from. You’re probably best just declining for now, as status ailments aren’t too common at this point and stocking up on the individual medicine can be more cost effective. Be sure to pick up the X Defense sitting behind the Pokémon Center, too, as it can be a bit hard to see.
You might want to stop by the Poké Mart so you can restock on Poké Balls and sell off your Tiny Mushroom that you picked up from Viridian Forest. Remember to buy Poké Balls in increments of 10, because for every 10 Poké Balls (any variety) you buy, you’ll also get a bonus Premier Ball, which functions like a normal Poké Ball except it looks a bit different visually.
The Pewter Museum of Science is on the northern end of town. It costs 50 to enter, although other than some flavor text and lore, there’s really nothing worth entering for unless you’re looking for something to entertain yourself with.
To the west of the Museum is a woman with a Slowpoke. She’ll ask a favor: that you watch her Slowpoke while checks out the Museum. Definitely say yes to that and you’ll be treated to a relaxing time watching Slowpoke and will be rewarded with a Big Pearl for your trouble, which can be sold for an impressive 4,000. Very nice! It has no purpose other than being sold, so feel free to sell it for some extra spending cash, although make sure that you hold onto at least 500 for something coming up later.
Follow the path south of the Museum to find the Pewter Gym. Make sure you’re healed up and that you have a Grass- or Water-type Pokémon on your team (there aren’t any Water-type Pokémon available at this point outside of trading, though), then head inside to take on the first Gym of the game.