Go to your GSTL. After my 60 days I kind of learned to just grab my break slip from guest service and jump on a lane. You figure out which lanes they're gonna ask you to be on (most likely the lanes closest to grocery which no one is on) but lately my store has been trying get cashiers on both softlines side and grocery. But for now I'd just find the GSTL or GSA on site and they will tell you what to do!
After a year and a half of cashiering, it's such a breeze. Have fun! Meet some new people!