At what time do I arrive ?
If your host indicated a time, arrive “around this time” : in France, it means “not before and until 30 minutes after” !!
What do I say :
just say “merci” when your host tells you “entrez”, “donnez-moi vos manteaux”. Add the typical “ça va ?” or “comment allez-vous ?” for a more formal situation.
Do I shake hands or faire la bise ?
If you are introduced to people say :
“enchanté de vous rencontrer”,
“je suis enchanté” (nice to meet you).
If you are invited for an apéritif or a meal, wait until your host tells you to sit down “asseyez-vous”. They might also tell you where you must sit.
Back to je suis invité / I'm invited