In my other life I teach organizing and decluttering

I have actually used a shovel to clear out a clients basement. It was a very big job!
An overflowing basement can take weeks or even months depending on the time devoted, the ability to let things go, and the quanity of “stuff”. Pick a starting spot in the room and work that section until clear. Used the do I use it, do I love it, does it make me smile principal. If soemthing does not meet these criteria, get rid of it. Keeping things for “someday” creates nothing but clutter and ultimately becomes a burden.