I can't even get a simple script to run

Okay, I used this tutorial:

I copied and pasted the big script it had there, saved it in my lua folder in my garrys mod folder as .lua,
started up gmod, opened console and typed “my_test_function”.
It said the command was unknown.

Now, my lua folder had 3 folders in it: vgui, includes, and postprocess.
I didnt have a auto run folder like it said where the lua file needed to be, so i made that and made a client folder in it and put the script in.
So… can anybody help? I don’t know how to get the script to show.

(User was banned for this post ("Wrong section" - mahalis))

Did you start a sp/mp server first?

It’s not supposed to be 3 folders but 3 files with the extension of .lua and you can copy and paste it with notepad++.