Hi.
Depending on the brand and model, it is often called "reading and resetting" or "X and Z reports". Look through your manaul for it. There will be many reports, so you need to decide which suit you. The first one in the list will often be best for most shops. Make sure you do the Z report, not the X or it will not be cleared for the next day.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cash registers.