Follow the trail to the northwest to get a free item, a Poké Ball lying in the tall grass. Go back to your starting point, and this time follow the path to the east. The first person you see won't have anything interesting to say, but the next person certainly will — he's your first non-rival Trainer battle!
Continue north along the path and you'll encounter a second Bug Catcher. After that battle, grab the nearby Antidote, and turn west into the tall grass. Zigzag your way westward through the trees until you see a signpost. Explore the dead-end to the southeast to get a Potion, then continue west past the sign. Defeat one last Trainer to reach the northern edge of the forest. Leave the gate to re-emerge on Route 2, and continue north to Pewter City.
Pewter City is a quiet city nestled in the northern mountains. Local attractions include the Pewter Museum of Science and the Pewter Gym. The Gym Leader is looking for challengers, and the kid blocking the city's east exit will drag you to the Gym if you try to leave. This is the first city to sell Potions, so stock up at the Poké Mart before challenging the Gym.
The Pewter Museum of Science is located on the north side of the city. It hosts a wide range of artifacts and exhibits, with a focus on fossil excavation and space exploration. Admission to the main building is 50 for a child's ticket. The laboratory next door is closed to the public, but return later and one of the scientists inside will give you the Old Amber. His colleagues on Cinnabar Island can use the preserved DNA inside it to resurrect an ancient Aerodactyl.
PEWTER CITY POKéMON GYM LEADER: BROCK
The Rock Solid POKéMON Trainer!