You win handily

You start the battle by having Charmander growl a couple of times to lower Blue's Squirtle's attack. He took a tackle in the process, but wasn't too bothered. Blue fumed and shouted at Squirtle to fight harder while you cheered on your Charmander.

Once you started having Charmander use scratch, you could tell the battle would end in your favor. A few hits later, Squirtle went down and your Charmander stood victorious. "Good job, Charmander! I knew you could do it!" You hug your pokemon companion as Blue returns her Squirtle to its pokeball with a look of disgust on her face.

"Fine, Red, you win this time. But I'll get you back, just you wait!" With that, she drops your prize money and storms off, leaving you and Charmander alone. It was a good start to your adventure, getting your favorite pokemon and some quick cash by beating your rival.

After congratulating your partner, you return Charmander to his pokeball and set off for Veridian City. It's the closest town that has a pokemart where you can buy some pokeballs, essential tools in your quest to become a renowned pokemon trainer and master.