Fantasy: I Am Extremely Qualified and Don't Need a System

What should I do if I travel to a fantasy world and the system I get is useless? PS. In order to promote my Chinese cuisine, there is still a system, but it is of no use in getting stronger. It is probably like a portable supermarket. This is the first time for the author to write in the fantasy genre, and he is not very good at writing about combat, so I will probably briefly touch on it. Please bear with me. The introduction is weak, please go inside. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.