I can't find the texture you have used in your texture course. I'm not finding any of the same textures in the course project files. If you could help me that would be great! I can't even find any RGBA online either...
RGBA is just a texture map with color and transparency. So if you created blue circle with a transparent outline and saved it as a PNG file you'd have an RGBA image.
The textures and materials used in this course are in the project files. If you go to the main page of the course you'll see "course files" in the tabs. At the top of the list you'll see "project source files".
Yes you import them. Most if not all the Unity project files are just a Unity project. So if you bring it into your own project or create a new one altogether it'll contain everything you need.
