The first thing we must know is that in the western music also there is classical music. We often get confuse that classical music means only Indian classical. Of course the western classical music is totally different from Indian Classical music. However, the musical notes in western classical music are the same which normally used for western music.
While in Indian classical music we use SA, RE, GA, MA, PA, DHA, NI, wherein In western music we use DO, RE, MI, FA, SO, LA, TI. The scale is the same in both western and Indian Music, only the written notes are different.
In western music one has to learn 'Staff' notes. The staff is 5 parallel lines in which musical notes are to be written. Here there are "Treble clef" and "Bass Clef" in which the notes are to write as "whole note", "half note or "quarter note" etc. The notes are written as per the timing or say beats.
Indian music notes are written in same pattern, we write Sa, Re, Ga..... with indicating on note like "Teevra", "Komal" or "Suddha". Like if we say natural note in western music, we will say "Suddha" note in Indian classical music. If we say "Flat" or"sharp note" in Western Music, we will say "Komal" or "Teevra" in Indian classical music.
It is just not enough to describe in writing unless you see the notes physically. So, I would advise you to get the Indian and western note and try to understand the differences.