Hello,
Thank you very much for choosing our theme and for contacting us.
1. You can translate all theme and plugin texts via PO file in WordPress. Here is a video tutorial that should help you translate your website texts with a Loco Translate plugin https://www.youtube.com/watch?v=D3NsDdMzsls&list=PLMw6W4rAaOgKKv0oexGHzpWBg1imvrval&index=3
2. Checkout is the Woocommerce template and our support does not cover the customization of the plugin’s templates, you will have to find a plugin allowing to customize the checkout or customize.
Best Regards