How do you know any explanation is correct from any source? That is not unique to LLMs.
This is not very hard, and we all used to know how to do this not 3 years ago.
https://www.youtube.com/watch?v=rdj_Fm4XM60
If a person writes a textbook, a tutorial, a blog post etc. which is that bad it won‘t be recommended by peers and a beginner will either not know it exists, or find see the bad reviews from peers. The beginner will then look for a different textbook, tutorial, blog post etc.
When self learning with AI, you don‘t get that. The best advice a peer can give you, is simply, do not use AI to learn stuff you don‘t already know.