How can LO open Corel Word Perfect documents?
Did you try the obvious - File | Open and navigate to the document you want to open.
In case you don’t have any WP documents (.wpd) on hand to experiment with, but want to know ahead of time if LibreOffice will work for these, the answer (in my experience) is “yes but” … you will lose some formatting, depending on the .wpd document. For the QuattroPro component of the Corel WP Office suite, the answer is also yes but … you will lose a lot of formatting and all of your charts. So you will have some reconstruction to do. But it will work otherwise. For Corel Presentations, I have no idea, never used it. Good luck. (IANAL but used WP for many years because of its many professional and business features.)