I am not sure how are you creating the groups and batches because right now I cannot see any groups on your website. When I checked I found out that your groups component is also disabled, refer:
http://prntscr.com/cbpyrc
For creating batches the groups component must be enabled and then create batches and follow our video tutorials on the wplms batches.
For customizations please use wplms customizer plugin only as it is never updated and your customizations are kept safe.
If you are saying about the text then use the translation plugin to translate theme, refer:
https://wplms.io/support/knowledge-base/translate-using-loco-translate-plugin/
This will keep your translations safe and you'll have to just sync files by clicking on sync button once after the update.
Let me know if this helps.