Wishing you the best of luck! I love the Iris shoe boxes for storing fabric. They stack nicely on the shelf and you can see what's in them. Longer lengths of fabric I fold in half lengthwise and roll them up on a 5" ruler. They fit perfectly I the shoe boxes.
It looks like you have a great space to work with. DH put shelving in our spare bedroom closets which hold some of my overflow craft items … like batting, etc. Get busy, but just tackle one step at a time so it doesn't feel overwhelming.