We usually have the aperitif in the living-room and then dinner in the dinning-room.
But if too many people are invited and the living-room is too small, just have the apéritif in the dinning-room.
Aperitif lasts at least 45 minutes, one hour is common. It's the first gathering time, people want to enjoy this moment and take their
Offer one or two drinks.
If you are the host, ask your guests what they want to drink :
« qu'est-ce je vous sers ? » or « Vous voulez boire quoi ? ». Then, list the drinks you have so they can choose.
If you are the guest, just use « je voudrais xxx s'il vous plaît ».
They also might ask you if you want some ice in your drink : « vous voulez des glaçons ? » / « je vous mets un glaçon ? ».
What to drink : for this special occasion, Champagne is a good idea, but you must choose a « champagne brut ». You can also drink a kir and kir royal.
What to eat : as it's a special moment, peanuts and stuff like that are ok, but French people would prefer some « canapés ».
"Canapés" are kinds of toasts with some « saumon fumé » or « oeufs de lumpe » on. You can also make some canapés with « foie gras ».
It depends on the menu of your dinner : if there's no « foie gras » during the dinner, you can have some for the aperitif, if there's no « saumon fumé » (smoked salmon), have it on the canapés....
If you're invited. Be careful !!!
Canapés look very good, but don't forget, it will be a long, long meal. Keep some space...