"Please tell best way to ear train"
Well, there is no best way to train your ears. There will be always different methods that work better for different people...
However, here are some tips:
- Get to know all the intervals.
There are a lot of ear training apps you can train your ears with. There you get the first impressions of perfect, major, minor intervals...
If you can figure out the intervals, you'll be able to play any song by ear in any key.
This is because the interval relationship is the same in every major key for example. So if you haven't perfect pitch, you won't be able to tell the exact note name or pitch of a note you've heard, but what you can train is relative pitch.
If you know "the second note is a major third below the first one, then the next one is a perfect fifth up..." it doesn't matter on which note you start the song, because no matter where you'll start, you'll always play the correct tune just in a different key.
- After you got your intervals, start simple!
Don't try to transcribe any pop songs with 20 instruments. Just take a slow piano piece and try to recreate it by ear. In my opinion the piano is an easy instrument to figure out by ear. When you get better and better, you go to other instruments and songs with more instruments.
Don't try to figure out all the instruments at once. Play it once and try to figure out the vocal melody line, then run the whole thing again and just focus on the bass line etc.
That's how I've learned it and I got better and better over time, but it's still hard for me to transcribe orchestral scores by ear for exammle, because there are so many instruments blending into each other and sometimes it can be quite hard...
- Don't think this is a one day process.
You won't get better unless you train it over and over again - It's going to take a lot of time until you will get good at it.