I think its much better if you read the official one at the webtoon website (and its not so cluttered like other illegal websites), but when youve caught up to the official ones, you can read the fans translations anywhere else
If you’re meaning what chapter to start with after finishing the anime, what I found online is around chapter 79. They say start season 2 chapter 0 of the webtoon.
I wanna know what chapter does the season 1 in the anime ends? I'd like to start over there