Between Two Notes
Sometimes when trying to learn a new tune we stumble repeatedly over a certain group of notes, or section of the song. It sometimes happens that after repeatedly messing up a section of a song while trying to play it, we actually learn to play that part wrong. We have unwittingly “practiced” in a mistake. Here's a tip for how to clear up this problem.
Find a place in the tune where you stumble or stall or have trouble going from this note to that. For example, from the third finger on A to the second finger on D. Play those two notes about ten times in succession. Twenty times really locks it in. You will never again have trouble with those two notes.
Maybe those two notes are with a group of four notes. Add one of those four notes to the two you just practiced. Play those three, ten or twenty times. Add the fourth note - play the group ten or twenty times in a row. Go as slowly as you need to go to get them right. This is an exercise in accuracy. There is no point practicing a mistake. Then play it a little faster. If for some reason you're still messing it up - go on to something else for an hour or two - doesn't matter what else - a different tune, mowing the lawn, playing with the dog. You need time for your brain to build up more of whatever it is it uses up when you're practicing music so you give your brain a breather.
With music although we learn songs and notes and carry those in our minds, our fingers and hands learn the mechanical motion of playing those notes on an instrument. A stumbling block in a musician's fingering is always between two notes - not the whole tune, not even a whole measure. As you go on to more songs you'll find that certain groups of notes - certainly couplets of notes - show up over and over again. So every time you learn one group, or couplet - it gradually becomes easier to get through a whole tune without so many struggles. You've already learned most of the fingering for it.