I challenged Brock, and I have to admit that I had a tough time against him. I used Pikachu against Brock's Geodude since I wanted to level up Pikachu some more, but things didn't work out. I had to swap out to Rattata and then to Squirtle to get the job done. Once Brock's Geodude was defeated, I had to battle against his Onix. I had Squirtle attack with a Water-type attack in order to make use of the type advantage, but Onix was able to stay in the battle. I had to attack it a few more times in order to defeat it. Once I had, I got the Boulder Badge from Brock as well as his Gym's TM, and then I left the Gym to heal my Pokemon. I visited the Pewter City Pokemon Center, and I saved inside after my Pokemon were healthy again.