I am a beginner learner in blender and I have been learning about texturing and UV unwrapping.

In this Brackey's tutorial, he adds basic materials before UV unwrapping the model. Similarly, I have accomplished this. However, after unwrapping, he manages to make the materials that have already been added into a texture that can be exported to Photoshop, to add greater detail.

I want to do the same thing, but I am using a much newer version of Blender.

Here is a link to the video where he adds the materials (at around 5:30): https://www.youtube.com/watch?v=qYKQwMc-WdE

Here is a link to the video where he starts unwrapping: https://www.youtube.com/watch?v=jLEpjSFHl4o

Any help would be much appreciated! :)