Check out this five-video course from Substance by Adobe in which you will learn the basics of Substance Painter.
This tutorial will teach you how to texture a robot asset from start to finish. The course is divided into 5 videos where each video builds upon the previous lesson. At the end of this course, you will have built a basic foundation for texturing in Substance Painter that you can further expand as you continue to learn and grow as a texture artist.
This course comes with all project files, as well as a full workbook, which details each step shown in the videos. Use this link to download it.