naturally, knowing the notes on the fretboard will help also. You should spend the time to memorize those notes, because that way you won't need to rely on trial and error to find the notes that you hear.

You will need to study music theory as well, as you practice ear training.

Those three skills are seperate, but work together in an integrated, systematic way.

When you know what key it's in (music theory) you will know how to listen to the intervals and chords of the music (ear training) and then instantly know where to find it on the guitar (fretboard memorization)

Hope this helps!