Page up / Page down scroll a page at a time. Up and down cursor keys scroll a line at a time. Home and End will go to the top / bottom of the page.
On the scroll bar, clicking above or below the ‘handle’ (the bit that scrolls) will page up / down. Grabbing the handle by clicking and holding on it will allow you to drag it up and down.
Many trackpads have some sort of scroll functionality, though it may be disabled by default. On mine, the very right-hand edge will scroll if I tap, hold and drag. On my work laptop there’s a ‘middle button’ which puts the trackpoint into scroll mode. Might be worth googling / looking for settings for it in control panel.