I will give examples of using some keys in MacOS on a MacBook that are not on the keyboard:
PageUp – fn + up arrow
PageUp (in the browser) – Space
PageDown – fn + arrow to down
PageDown (in the browser) – Shift + Space
Home – Command + up arrow
Home (in the terminal) – fn + left arrow
End – Command + arrow to down
End (in the terminal) – fn + right arrow
By the way, to select non-editable text, for example in Midnight Commander, you need to hold down the Option key and circle the text with the mouse.