While using vuejs with vue what I find very important is dividing states into modules. eg: auth module, user module, status module, post module. each with their own state, actions, mutations, and getters.
for more, I recommend referring the following video: https://www.youtube.com/watch?v=5lVQgZzLMHc
you can also check the official documentation for more at https://vuex.vuejs.org/guide/modules.html