No, the noun 'party' is a common noun, a Word for any party of any kind.
A proper noun is the name of a person, a place, a thing, or a title; for example:
- The New Zealand National Party Headquarters, Wellington
- The Labour Party, One Brewer's Green, London
- Berwick Manor Restaurant & Party House, Columbus, OH
- "The Life of the Party", 1937 movie starring Joe Penner
- "Life of the Party", 2005 movie starring Eion Bailey
