Are there differences between Web Novel, Light Novel and Manga of Mushoku Tensei? I'm currently reading manga and I was thinking to switch to LN or WN so I'm wonder to what I should read WN or LN.

I'm current in chapter 15 in manga.
As far as I know, the manga follows the same path as the web novel with much skipped content. I don't know about the light novel but I read somewhere that there are some differences. And according to Wikipedia (link), there exists a whole volume between WN volumes 6 &amp; 7, that covers Rudeus' adventures following Eris' departure.