The Pokédex section has all basic information for you to check where to obtain all the Pokémon species and forms from the entire game series of all generations. You can view each entry by clicking on the Pokémon icon, or by searching for a Pokémon by name, number, or type.
Type anything or narrow-down your search by including prefixes like
type:. If you type for example, just "ice" it will match everything, including "Jellicent". You can also enter different criteria, separated by space (in that case it will search using an OR condition).