In our old classroom system my classes included a section called Pre Class Videos, that had introductory lessons about brushwork, layer masks, opacity, blend modes, and lightening dark photos.

Those lessons are still available, but have moved to a free class called The Fundamentals. Any references to Pre Class Videos will be covered in The Fundamentals. You can access the class here if you already have it in your list of classes, or sign up for it for free if you don’t.