Please, make sure you have checked all the server requirements before the installation – https://xstore.helpscoutdocs.com/article/60-xstore-theme-requirements
In case if automatic plugin installation fails, you can install them manually via your Dashboard: Plugins > Add New > Upload Plugin > Browse plugins archives. Or via FTP, by uploading and extracting the plugin zip files into wp-content/plugins folder – https://www.8theme.com/download-plugins/
Try to install demo content from XStore > Import Demos.
Let us know the result.
If you need any further assistance, provide URL and temporary wp-admin access.
