A child theme inherits the look and feel of the parent theme and all of its functions, but can be used to make modifications to any part of the theme. In this way, customizations are kept separate from the parent theme’s files. Using a child theme lets you upgrade the parent theme without affecting the customizations you’ve made to your site.
Each parent theme has a child theme available in the download package. To make things simpler you can download the corresponding child theme of the parent theme you’re using here.
More details on how to work with a child theme can be found here: