Nice last name is: joli prénom
vous avez un joli nom
Son nom de famille est... [Her last (family) name is...]
you say 'agréable'.
You would say "Quel est votre nom de famille?" in French to ask someone for their last name.
'your the nice one' in french is 'votre la belle'.
In French, 'bon voyage' means 'have a nice journey'.
The only correct plural for French is French. "Frenches", as you say, or 'Frenchies' is a derogatory slang term.
When it's a first name or a last name it's the same as in English
It tastes nice is "ça a bon gout" or "c'est bon" in French.
allons à Nice
Travail
gentil/gentille