We would like to point out the importance of using the Child theme for those who is willing to customize the source files in order to adjust theme to suit specific preferences and project. The fact is that we are going to keep upgrading and improving our theme and there are lots of updates coming out and you would definitely be interested in getting these updates on your website, so with said in order to prevent the loss of your customization added through altering source files we strongly recommend to use the CHILD theme for customization purposes.
The theme bundle is packed with the child theme zip already so you can get that installed through WordPress and then start customizing required features through files in the Child theme. The child theme zip could be found in the theme folder.