The pattern to memorize first
Think in four-hole groups. Blow gives C, E, G, C. Draw gives D, F, A, B. Holes 1-4, 5-8, and 9-12 repeat that shape in higher octaves.
Blow: C E G CDraw: D F A BSlide: every note moves up one semitone
Where beginners should start
Start in holes 5-8. That middle octave is easier to hear, easier to control, and maps cleanly to the C major scale before you move to the low and high ends.
Use the chart as a practice tool
Do not only read the chart. Pick one four-hole group, play each note slowly, then say the note name and breath direction out loud. That turns the chart into muscle memory.