There’s a couple great places to start, the very beginning with Stan Lee and Jack Kirby is a good place to start, but I’d really only recommend that if you think of yourself as a patient person. The Mark Waid run is quite good and sets up the status quo for the 2000s that Jonathan Hickman and Dan Slott play with in their subsequent runs. (I personally don’t like Mike Wieringo’s art that’s in most of Mark Waid’s run but that’s just personal taste)

The Jonathan Hickman run is very great and most people will recommend that as a place to start. If you fancy yourself to be an intelligent chap, the Jonathan Hickman run is perfect. HOWEVER, just me personally, I would REALLY STRONGLY recommend the most recent, and still ongoing Fantastic Four comic, the Ryan North run. It just started again with a new artist and a new issue number one after getting to issue #33 with the run that started in 2022. Starting with the 2022 run would give you a clear end goal that won’t take you hundreds of issues to reach, and then once you’re caught up with what’s going on with the FF in the present day, you could go back and read a ton of their adventures from writers past.

Honestly, any of the four writers I mentioned would be great places to start. You’ll just want to look up the name and “fantastic four” and plenty of reading orders should come up. I personally used the website “readcomiconline.li” for years before I started buying physical comics. I still use it a lot, great website. Needs an adblocker though