Tutorial for My First Multiplayer

[dongawonga]

I keep walking through the Coral Spikes Big even though it should be collision proof. I tried all the settings (Force On/Off) and nothing works.
Also, it says, "Search for UI Text Box under Game Instructions in the Hierarchy." and there is no UI Text Box in the folder.
It says that you can select several objects and drag the materials onto the group, but I selected 3 walls next to each other and dragging and dropping only paints one wall at a time.
This tutorial needs to be updated. I want to learn how to use Core, but if the tutorial is flat out wrong, I don't want to bother. I am about to give up on this.