So here are basic points about child theme usage with our theme
1) If you need to customize any theme files or add a lot of CSS changes to your web-site you need to use child theme.
2) Here is the link that demonstrate how it works https://codex.wordpress.org/Child_Themes
3) You don’t need to create child theme from scratch because we already made it for you (you have found in in theme package downloaded from themeforest)
4) When you install child theme and activate it all widgets and menus configuration will be lost. It is not our theme bug, it is default WordPress behavior.
5) So after activating child theme you need to add your widgets to all widgetised areas in Appearance -> Widgets again.
6) When you are done with child theme set up, you can freely update PARENT theme without loosing any configurations or changes made in child theme files.