Changing/editing “hardcoded” theme texts
There are lots of texts used in the theme that are “hardcoded“. In some cases perhaps editing via Child theme might be a good solution, but in general, a very easy solution is to simply use this plugin called “Loco Translate” https://wordpress.org/plugins/loco-translate/ which will scan all these texts and allow you to edit them on the fly.
Here’s a video explainer https://www.youtube.com/watch?v=GHqJiuH-zfE or read a tutorial https://optimizerwp.com/documentation/how-to-translate-theme-using-loco/ .
Using PO Edit:#
You can use WPML plugin which is the most powerful multilanguage plugin for WordPress. More on http://www.wpml.org/ .