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.
The 'Solo Leveling free novel' is mainly about a guy's adventure in a world with dungeons and monsters. He begins as a nobody in the hunter community. However, things change when he gets an unusual power - the ability to level up on his own, which is quite different from other hunters. This new power sets him on a path of facing increasingly powerful foes. Along the way, he also meets different characters, some become his allies, while others are his enemies. The story is filled with action, suspense and a lot of character development.
The Solo Leveling manga has a considerable number of chapters. But the exact length can vary depending on how you measure it, like in terms of page count or story arcs.