Well following an altium tutorial when working with KiCad might not be the best idea. The workflow is quite a bit different. I mean it can help if one already knows how to use KiCad but needs additional info regarding the arduino steps (doubtful) but really only in that case.
So maybe start by learning KiCad with tutorials for KiCad. We even have some on the forum (if you like me prefer reading over videos, otherwise YouTube is your friend)
- Tutorial: Introduction to PCB design with KiCad version 5.1 (Getting Started)
- Tutorial: How to make a symbol (KiCad v5.1.x)
- Tutorial: How to make a footprint in KiCad 5.1.x (From scratch)?
If you want more precise help, then you will need to give us more details. What exactly are you trying to do right now? What do you expect (from the altium tutorial) to be necessary to achieve that?