Thank you so much for you question. You have different method to translate the “You are here” on the breadcrumb. Please prefer the suitable and simple method.
1. Create a mo file of the theme and add inside the languages folder. https://codex.wordpress.org/I18n_for_WordPress_Developers
2. Just edit that file,
breadcrumb.php. Write your own text instead of You are here.
Note: We strongly recommended you to use child theme for theme customization or edit.
If you have any further query, please feel free to ask.