If you need the mockup of a packaging box for printing, then I can share with you a link to one useful resource. Here
https://www.ls.graphics/free-mockups/box-packaging you can find free samples of printed products. I think that you can significantly reduce the time to complete this work and since all the mockups on this site are done by professionals, you can be sure that the sides of the disassembled box on the mockup are correct.