Child Theme via “Child Themify”

Hi, Noob here.
I just created a child theme via Child Themify (Storefront Theme). I had already made some changes to my site (colour, background, logo, etc. – No Coding) when I realised I should make a child theme. Child Themify provides some options regarding which files to copy over to the child theme. At first I selected none, but I lost some changes. I then went back and did the process again, but this time I selected all the additional files.
Is this advisable? Or should I only select some of the,? Which ones?
Any assistance would be appreciated.