Child theme is added in the theme package https://www.8theme.com/demo/docs/woopress/#!/2_child_theme .
You don’t need any images for child theme in wp-admin panel. There is already a title “Woopress Child”.
Slowness of the site may be caused by the 3rd-party plugins you’re using.
Also try to switch to WordPress default theme and check if the site loads the same.
