Personally I love the Quick Access panel in Windows 10 File Explorer, but if you don’t want it, you can turn it off.
What is it?
Quick access is a small panel that stores your favourite folders and files and gives you quick access to them as the example here shows.
It is set in the View Options
In a File Explorer window go to the View ribbon and select Options and then to option to Change folder and search options as shown below
That will lead to the actual place where you decide what to see in your File Explorer.
As you can see here simply select or deselect the way you prefer. If you change your mind, go back here and modify your choices.
Adding your own folders to Quick Access was described previously in Feb 2016 in the article on my blog here: