I'm planning on storing the majority of the texts for my blog in vuex for fast loading speed. Is this a good idea especially for SEO or should i create individual routes for all posts? I definitly do not know alot about SEO and I'm also new to vue/nuxt, before I've used mostly vanilla javascript.
You can but its defenetly not recommended to do it like that.
Nuxt offers a good module for writing blogs https://nuxtjs.org/blog/creating-blog-with-nuxt-content
Works for static sites too. They get pre-rendered.