You can customize your trainer avatar, get a starter Pokémon in the form of Bulbasaur, Charmander or Squirtle, and are sent on your way by the new Pokémon Professor, Professor Willow. (Noted: you can get a Pikachu as your starter too as there's a trick to it.)The map in the app also indicates where the nearest "PokéStops," areas where you can pick up items such as Pokéballs, and gyms, where you can do battle with other trainers.
However be careful when playing the game. As a police station in Darwin, Australia, had to issue a warning on their Facebook page when they found that their building was the site of a PokéStop after several people tried to enter it in the name of Pokémon. Police and state officials have warned players about paying attention to their surrounding, and in a bizarre story, a teenage girl may have discovered a dead body while trying to catch a water Pokemon as a result of the game.
While the launch may have given fans worldwide the hype, many trainers are unable to log into the game, while others can do so but run into trouble when actually trying to catch Pokemon. In reality, it's a disaster launch. Hopefully the Pokemon company and Niantic can resolve the issues at hand and roll out the official launch worldwide.