Usta be you could load all kinds of free icons for your desktop. Now all these so called "free" sites seem to be little more than scams to sell you stuff as it's almost impossible to download any of their "free" icons, especially in a usable .ico format!

However Win 10 does have some more stashed away in the following location:

What I do is copy that address link into a word file and save it in my documents. Then, whenever I right-click on an existing desktop icon and get into the "properties/change icon" box, I substitute paste that copied link into the upper address slot, click OK on the bottom of the form, and presto; Win 10 then provides more icons to brows thru than their usual sparse list!