Personally I would read the Stormlight series first, and then read all of Sandersons other series.

Then hunker down and read WoT. Then go back and re-read the Sanderson Cosmere again.

WoT gets very stagnant in the middle books, whereas Sanderson keeps the flow going.

I started reading WoT years and years ago, when you had to wait a year or more for the next book to come out. When Robert Jordan passed away, and Sanderson finished the remaining books, I became an instant fan of Sanderson. Hadn't read anything of his at that point.

I've re-read both series, and the entire Sanderson Cosmere is one of my favorites.

WoT is a classic, it is bit of a grind, but it's worth it.