Hello,
You need to translate the theme and plugins. About Checkout, translate strings for WooCommerce plugin.
You can use Lightshot screenshot or Gyazo tool to make screenshots and share links here.
1/ “About Author” – it is translated – https://prnt.sc/bWqB2j2EWBD9
2/ Provide FTP access, we will check the situation with “Reviews” more deeply.
3/ Header Builder > Search > Platzhaltertext
4/ Header Builder > Cart > Mini-Cart Promo-Nachricht
5/ This text comes from Mailpoet plugin
Regards