Role of Layers
 

Adobe Photoshop is one of the most popular graphic design tool, how can we create and merge multiple layers in this tool ?

If you are using Photoshop to make changes to your photos, this is fine, but if you want to create a real mockup for printing, another software is best. Although, in principle, you can always get the first layer by downloading one of these files https://www.ls.graphics/free-mockups/brochure-mockup and opening it in the program. I use these mockups to get the right size and how it will look on paper or fabric. This saves me a lot of time, because basically reworking an order is the main loss line.