After removing the cork and placing it in front of the guest who ordered the wine or pocketing the screwcap if that’s what came on the wine, you should pour a very small amount (an ounce or so) into the glass of the person who is deciding if the wine is ok to serve to the other guests.
Sometimes the guest host who ordered the wine will defer the initial taste decision to another guest at the table.
When approved, you may now pour a regular amount of wine into each of the glasses of guests who are drinking that wine.