How do I eliminate the footer white space so I can type to the bottom of the page??
This question is about which app? You tagged common but the procedure is different in Writer, Calc, Draw, Impress and Base. @Zizi64’s answer is valid for Writer. Edit your question to mention the relevant application(s).
In any way, retag to replace common with the application name. Press Rnter twice to exit retag mode. This will allow the community to more easily select your question when looking for a similar problem.
My answer is valid for Writer, and it valid for the Calc. The Calc Page Styles contains same properties.
The Draw and Impress has only one Page Style per document, and that Page Style has not Footer property. The Margin setting are available from the menu Page - Properties.
In the Impress: Slide - Properties.
(Menu items are from the LO 6.1.6)
You can modify the Margins, and the size (height) of the Footer in the applied Page Style.
Note: some (most of?) printers can not print texts what are located too close to the bottom of the paper.
Or: if you want not any Footer, the you can switch it OFF in the Page Style. And you can shrink the bottom Margin.