You will encounter wild Pokémon on the field in the Wild Areas. However, the Pokémon you encounter will vary depending on your location in the Wild Area as well as the weather. If it's raining, for example, more Water-type Pokémon will appear
Pokémon typically react differently to you based on the species. Some will charge at you, others will run away. You can approach them slowly using the Control Stick or whistle to attract their attention.
We'll compile a full list of the Wild Area's Pokémon as the game approaches launch