I have been using libreoffice for ~10 years and most docx are in this program. Recently transferred data from MacBook Air via WD My Passport to late 2014 iMac. Docx are opening in textedit instead of libre office. Fix?
Did you already install LibreOffice on your MacBook Mojave OS? If yes - then the file association of your files to an application may be wrong. How to change? → see this one How to Manage File Associations in macOS - MacRumors (there are for sure other sites to explain this)