The 52 white keys on a piano keyboard are called according to the name of each key’s associated note. Notes range from A to G ascendingly, so letters increase moving to the right on the keyboard (as in A → B → C) and decease moving to the left (as in C → B → A). Furthermore:
Once you reach the end or beginning of the note sequence, it repeats. So when moving to the right up the keyboard, G → A → B, whereas moving to the left yields A → G → F.
The 36 black keys on the keyboard represent a half-step difference in tone between white key notes. A sharp (♯) is a half-step up, and a flat (♭) a half-step down. Therefore, the black key notes have two different possible names. For example, the black note between F and G could either be called both F♯ or G♭.
Easily locate the C note on your keyboard by finding the white key immediately to the left of a group of 2 black keys. The C key closest to the middle of your keyboard should be middle C, which is a central note for most beginner level songs.