Where can I access a Tutorial covering Calc Equations?

I desire to show a % value…but, how express that in Calc?

To display a value as percentage apply a percent number format to the cell, Shift+Ctrl+5 or from the toolbar or menu Format → Cells, tab Numbers, Category Percent.

Other than that, Calc guides are available at Calc Guides | LibreOffice Documentation - Your documentation for LibreOffice in several languages.