The Weakest Adventurer Becomes the Strongest is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

A mysterious dungeon has appeared in this modern era?! Adventurers challenge this dungeon in the pursuit of their dreams of getting rich quickly. From the weakest to the strongest! Aiming for the top by levelling up! The more you fight, the stronger you become in this battle saga!