So i went to talk to the boss at Winn-Dixie now what? And when to go back?

So I filled out an application on line for Winn-Dixie and i decided to walk into Winn-Dixie and i asked the manager if they were hiring and that i had filled out an application on line. Well he told me that "They are full right now. But if u really want this job and are serious then keep checking in with me". Thats my problem when do i go back in there and ask him again? and what do i say? im only 18 and this is only my second job lol scared