Hello,
I have researched for days on this and havn’t found a sufficient answer. I’m basically looking for a script to attach to my GUI Texture to rescale it pending on what the screen size is. Would anyone be able to help me?
Thanks so much 
Use Screen.width and Screen.height. More information in this similar question. You may also want to use Screen.dpi (especially on mobile devices) to resize your GUI according to a certain physical size.