I did this 0,0,0 step only to show briefly how the setup works.
When in viewport you can also press “P” to display the nav mesh and check if the point you are giving is valid.
In the tutorial that worked because I knew exactly where my origin is and that there nothing obstructing it. Normally you would try to give coordinates (or like I did later actors) that are reachable.
Happy you folks solved it! Good teamwork!