Right at the start of the tutorial. At time 0:34 the tutorial start of with "to create a basic material click this button" ... But wait how to I see that interface on screen. You cannot expect your new user to know how to get to that UI interface ... your tutorial need to be as step by step as it can be. In good details.…
Ah, yes! You'll definitely need to click the Get Project Files button on the tutorial page before you're able to proceed. The Base Creator shows up for you because you have nothing loaded yet. Interesting rust material! Let us know if we can do anything for you going forward, please. :)