I can't believe that no one picked up on this. You say you have long finger but using a small guitar.

Firstly how old are you. More than 11 = full size guitar.

Very new beginner 3 chords. A , D and Emaj chords. You shouldn't have any issue with finger positions on these chords.

When doing A switch fingers 1 and 2 positions. It's a little easier.

IF you are doing finger exercises for frets in 1 to 4. YOU DO NOT NEED TO KEEP YOUR FINGERS IN THE FRETS WHILE REACHING FOR THE OTHERS. Don't try to reach fret 4 while still keeping 1st finger in fret 1.

You are a "VERY NEW BEGINNER". Very basic exercise is MORE "where does my finger have to get to to play each note correctly. It training you head to place each finger where it's supposed to touch each string in each fret. Not get my hands to reach fret 1 and 3 or 4 at the same time.

If you are doing any more than learning A,D and E chords and exercise frets 1 to 4 finger placement . I suggest don't.

Practice A D change

Practice A E change

Practice D A change

Strum and pick make sure all is clear.