I would like to ask, how did you make the red frame with white background behind the first book of digital photography and shooting and processing skills?

As long as it is not in the background layer.

Double-click the layer to be stroked to pop up the dialog box.

There is a "stroke" at the bottom.

Click. Select the desired color and resize the edges.

Then make sure.

Grasp by yourself

By the way, there is also an external light that belongs to strokes.

In a word, it is much more useful to explore for yourself than to be told a lot by others.

I hope it will help you (* _ _ *) ...