Hello, Cristina
We added a video in documentation, Loco translate plugin can be simply installed and it simplest way to translate the theme and XStore Core plugin – https://www.8theme.com/documentation/xstore/theme-translation/base-theme-translation/
To provide wp-admin access, you can create a new user account with administrator role via the Dashboard, and provide us with the username and password via the Private Content area.
Once you provide temporary wp-admin access, we will be able to check the situation with translation on your site more deeply and assist you.
Waiting for your reply.
Kind Regards,
8theme team