Im trying to learn sax, I've already got a sound out of it, but how do I change the pitch of the note, like a high octave A and lower octave A?

I also have really tiny hands :< I have an alto sax so its not as big of a feat as tenor or bari...or contrabass D:

Btw, this is my third instrument. I play flute and guitar, but my forte is flute(3 years) even though I've been on guitar for about 5 years lol