Once you have started a new game, Professor Oak will introduce you to the world of Pokémon. Choose your name and your rival's name, and you'll be whisked to the wonderful world of Kanto.
Once you spawn in your humble home, head left and interact with A with the box thingy. This is called a PC, and it holds items. Now, there's a Potion, which heals Pokémon. Head down the stairs, and outside.
Here is Pallet Town, a small city filled with, well, not much. On the right is your rival's house, and under it is Professor Oak's Lab, where the professor will give you a Pokémon! Head there, and— He's not there. Just your rival, loitering around. Oh, well. Leave and head north to the grass. Just then, Oak, the professor will stop you! He states that Pokémon are dangerous and that you need one for your own protection. Then, a wild Pikachu will appear! Oak catches it in time. With the Pokémon out of the way, Oak will lead you to his lab for a Pokémon.
Professor Oak's Lab
Following Oak to the table, you then see your rival, inpatient and ready for a Pokémon. Oak then (to your rival's dismay) lets you choose the lone Poké Ball on the table. Go ahead and snag it— Your rival pushes you out of the way, and gets the Poké Ball anyway. Great. Oak then gives you that Pikachu he caught. Good, we have a Pokémon, so leave the lab..... Just then, your rival issues you to a battle!
Remember the potion you took out? Use it here if needed. If you want the Eevee to evolve into something different to take to your advantage, see the section below.
|Lv. 5||-||Lv. -||-||Lv. ?||-||Lv. ?||-||Lv. ?||-||Lv. ?||-|
|Ability: Unknown||Ability: Unknown||Ability: Unknown||Ability: Unknown||Ability: Unknown||Ability: Unknown|
|Item: None||Item: ?||Item: ?||Item: ?||Item: ?||Item: ?|
Eevee will simply use both of these moves, so simply attack.
So, if you want Eevee to evolve into another type to your advantage, follow this! For Jolteon, win this battle and win the Route 22 battle. For Vaporeon, lose this battle and lose or skip the Route 22 battle. For Flareon, win this and lose or skip the next battle, or lose this and win the Route 22 battle.
Leaving the Lab
Once the battle ends, your rival will walk away. Leave— Wait, the Pikachu's out of the Poké Ball! Oak explains that Pikachu doesn't like Poké Balls and prefers to follow you. You might think of this that it is nice of Pikachu to do such a thing. But, just talk to Pikachu behind you, and he'll express his anger. You'll be friends soon.
Anyway, head out of the lab and head north, towards the grass.
Welcome to Route 1, the first route you'll face. There's a bunch of Pidgey and Rattata here, but you can't catch them yet; we need Poké Balls. There's a guy on the left side of the road here. Talk to him to get a Potion. Continue up the route until you reach a city. Viridian City.