That is the word you should focus on when thinking about GA4. You read ‘migrate’ or ‘upgrade’ as it relates to moving from Google UA to GA4. But that is not the case.
You need to think baby steps. Things are very different, but not in a bad way. Learn to know the differences. Lay down the foundation (e.g. create and launch a GA4 property), be thoughtful, but don’t overthink your GA4 implementation.