Migrating my blog to Sanity's headless CMS was not as easy as I though it would be, and I did struggle through part of it. The blog post that I have linked below is somewhat similiar to how I ended up integrating Sanity into my project. Groq is not too bad of a query language, once you get the hang of it.
I find Next.js's documentation to be adequate, but it is far from being as good as Tailwind's documentation. Their error messages are fairly vague as well. I still recommend playing around with the stack.
I am sure that I will be using Next.js for quite sometime for anything that requires SEO, but I will be using Vite as my build tool in the future instead of Create-React-App(CRA). I will probably do a post on that in the future.