For this you need to translate the "Take this course" button to "Enroll Now".
Please refer this article on translation:
https://wplms.io/support/knowledge-base/translate-using-codestyling-localization-plugin/
The CodeStyling Localization Plugin seems to be off the Wordpress Plugin repo. Can you suggest some alternative or a way to get it working somehow?
Codestyling plugin is provided in the attachment of that article.
If you do not want to use it, then you can use loco translate as an alternative, refer:
https://wplms.io/support/knowledge-base/translate-using-loco-translate-plugin/