Squirtle was my first starter... However using the extra copy me and my friends all used to get the other starters I had Bulbasaur and Charmander early on as well. My play style has always been the same, level up all Pokémon I own, not just on my team, to the next multiple of 5 between each town. So by the time I faced Brock all my Pokémon were at level 15. I also attempt to catch every Pokémon, which has led me to purchase both copies every generation and trade them all over to one version, which was incredibly annoying in Gen 3.