Alright let's talk about notes on the 6th string of the guitar. One of the things that helps guitar players remember where they are is the concept of dots and inlays. So you notice that I have inlays as well as dots on the third, fifth, seventh, ninth and twelfth frets. Each one of these corresponds to a whole note except for the ninth so let's ignore that for now, but if we just look at three, five, seven and twelve, we have a G, A, B, and E, that gives us about half the scale as far as natural notes, what we're missing is D which is on the tenth fret, C on the eighth fret, and F on the first fret. So I would say start with three, five, seven and twelve, memorize those, G, A, B, E.
Alright then add F, C, and D. F, C, and D. If you play all of these together they're the same note that you'll find in the C major scale, the white keys of the piano. I might go up these notes with one finger, and sliding, just to make it sound like music. Descending. These also correspond to power chords with the root on the sixth string. If you have those memorized you've pretty much memorized most of the notes on the sixth string, all you're missing are the in-between notes, so in between F and G you have this note which can be called F sharp, or G flat, more commonly it's called F sharp.
In between G and A you have A flat or G sharp, more commonly called A flat. Between A and B, A sharp or B flat, and then we're back to this inlay here, which is between C and D, so that can be C sharp or D flat. OK, so once you've memorized all the natural notes then you need to go through and memorize the accidentals, once you've got those you should be able to memorize every note on the E string. E, F, F sharp, G, G sharp A flat, A, A sharp B flat, B, C, C sharp D flat, D, D sharp B flat, and E. And those are the notes on the sixth string guitar.