2. This text should be available in the translation of the XStore Core plugin.
Go to Loco Translate > Plugins > Core plugin > New language and create the translation. If the translation is already created there, you need to update translation files – https://xstore.helpscoutdocs.com/article/103-translation-files-update then you will be able to translate untranslated strings.
Mentioned strings are related to XStore core plugin. So, you need to make sure that you translated them in Loco Translate > Plugins > XStore core, and make sure tgat you pressed not just Save button for the translation but also Sync button to make translation up to date. If it doesn’t help then provide WP Dashboard access to your site. We’ll check and help you.