Pokémon Let's Go Pikachu and Pokémon Let's Go Eevee are re-tellings of the classic Yellow Version. As such, trainers cannot choose the typical Kanto Region Starter Pokémon — Bulbasaur, Charmander, ...
Pokemon Let's Go might be all about Pikachu and Eevee, but we wouldn't blame you for wanting a classic Kanto starter Pokemon: Bulbasaur, Charmander or Squirtle. Luckily, we know where to get them.