If you know Vue 2, Vue 3 will be easy to learn, as well. There are some more advanced features you can choose to use if you want, but I guarantee you could pick it up really fast. This isn't an AngularJS -> Angular sorta change.

Also, give it a few more months before building anything non-trivial. Some of the more popular libraries for Vue 2 still need to up updated for Vue 3 (vue-router, vuex, for instance).