how can I clear system files I don't need

Michaeldaly wrote:

I am trying to find where I can delete system files I don't need on my Mac book pro

That is not a good idea. There are no system files which should be deleted from a normally functioning operating system.

How do you know what system files you don't need? Leave system files alone.

I strongly suggest you leave system file alone. Deleting them is a good way to cause serious problems on your Mac.