You can try some official e - book platforms like Amazon Kindle. Sometimes, it may also be available on certain online reading communities dedicated to novels.
The story of Solo Leveling is about a weak hunter named Sung Jin - woo. In a world filled with dungeons and monsters, he starts off as an E - rank hunter, which is the lowest rank. But he gets a mysterious system that allows him to level up and become extremely powerful over time. He faces various dangerous dungeons and strong monsters, and gradually rises to become one of the most powerful hunters in the world.
You can start from the chapter where the anime ended. Usually, there are online forums or manga communities that can give you the exact chapter number.