Get the laundry baskets and start sorting! Grab a trash bag for items to pitch. A trash bag for items to give away/donate. Large zip locks for projects. You can buy large ones at Lowes! Plan how you want to organize your storage. I feel your pain. I have been there! Be realistic on what to keep and what to get rid of. A place for everything and everything in its place became my motto. Always a work in progress, btw.
sandy