Lots of good advice given so far for you ANON.
I don't play squeezy buttony things myself, so as far as the technicalities are concerned I would have to guess.
One of the best quotes in this thread was John in Kanzas commenting about "playing with it". Can I add - They call it playing because it should be FUN.
With a buttony push-pull thing (with different notes in and out) I would suggest you need to find games(exercises?) which help you to locate a particular note without needing to think about where it is. Playing a sequence of notes from a scale is one good practice, it helps your fingers to locate them without engaging the conscious brain. Select sequences which occur in real tunes, and you are already half way there when the particular run appears in the melody. NOTE WELL - patterning brain and fingers takes time and lots of repetition. You may repeat the same sequence badly for a couple of weeks and feel as if you are making no progress, then SUDDENLY one day you CAN do it - like magic. What actually has happened is that all the attempts have finally "burned" a sequence into your brain. It is like watchig a baby learn to walk. They cannot walk unless they have done all the getting it wrong first.
Most people who try to learn an instrument give up before they reach the point when the brain patterns itself to do things automatically.
Quack!
Geoff the Duck!