As you can see the Piano basically have the combination of black and white keys placed in some specific order.
The black key’s are specifically ordered as 2 key’s followed by 3 key’s depending on the number of keys your piano have.
Find a pair of two black keys. The first note to the left of this pair of keys is C, the next white key is D, followed by E, F, G, A and B. Label the white notes in the order, C, D, E, F, G, A, B. This just keeps repeating till you run out of keys.
The black key to the immediate left of a white key is flat (♭) while the one to the right is sharp ( ♯).

The basic Western keys are (C, D, E, F, G, A, B) flats and sharps.
Flats are C D E F G A B .
Sharps are C# D# F# G# A#.

For beginners, this is the website which will teach you the piano basics.
The notations whicha are commonly used all over India are called as ‘Sargam’ Notations.
Aaroh :- S-R-G-m-P-D-N-S’
Avroh :- S’-N-D-P-m-G-R-S

It is also called a singing exercise with notes.
Sargam is also a vocal exercise in which the notes are used.