Mushoku Tensei: Life and Strife.

Based on the original series Jobless Reincarnation from Rifujin na Magonote. I do not own the original series nor the cover. What would you have done if, from the moment you entered this new world, you knew it was going to be a happy ending anyway? Laurel woke up, completely unprepared for this new reality—that he had already been dead and got reincarnated, even. Now, in this unfamiliar medieval fantasy, he must live and navigate this world. Somehow. As he regressed back into a toddler, he must learn how to live properly using his second chance: a life different from the one he had previously. — Description from novelcodex.org