There may be a few ways. On my XPS, I can go to Windows Settings | Devices | Touchpad | Additional settings opens a panel that has a Disable button to disable the touchpad. You may also be able to reach that panel via a touchpad icon in your systray. Your keyboard may have a secondary function on one of the function keys that toggles disable/enable the touchpad. On my XPS it is invoked via Fn + F6. Look on your function keys for a secondary icon that could be a touchpad. If neither of those works, you may be able to disable it from Device Manager.   
Is there a quick way where I can disable the touch pad? Or for that matter, disable it permanently?
Inspiron 15 5620 - how to disable the touch pad