Myriad Realms Store Owner of Harry Potter

Ten years have passed since crossing over to the United Kingdom in 1981. Initially, I thought I could exploit my future knowledge after being reborn in the past, achieving financial freedom before turning 30. The result was that on the day of my 11th birthday, within my mind emerged a ‘ding’ sound. “Myriad Realms Convenience Store has opened, requesting the store owner to accept the first mission.” Apparently, an entirely new and unknown future is unfolding. However, what the hell is with this Hogwarts Acceptance Letter in my mailbox? σ（°△°—）