How do I clear space in my OS drive?

i’ve been trying to clear storage space in my OS drive which is a 128gb ssd (i believe) and its not working for me

when i am in “C:\Users” and check the properties it shows that the size is 41.3 gb and the size on disk is 41.5 gb

but when i mouse over the user folder which is named “zachary” it only shows thats the size is only 5.90gb

So what do i do to get more free space because my drive is left with 20gb of free space :/