On most System76 laptops, press Fn+F1 to turn your laptop touchpad on/off. On some Pangolin models (pang12, pang13, pang14), press Fn+F6.

To configure your touchpad, press the Super key (/), then type Mouse & Touchpad and click on the result.

After scrolling down to the Touchpad section, settings such as the touchpad speed and click methods can be configured.

GNOME Tweaks has a few other settings for the touchpad (for example, changing the acceleration profile.)

GNOME Tweaks can be installed from the Pop!_Shop (Pop!_OS), Ubuntu Software Center (Ubuntu), or from the Terminal with this command:

sudo apt install gnome-tweaks