Yes, it is a noun; it is a proper noun because it is the name of a person.
Yes, Alison is a proper noun; a person's name is always a proper noun, first and last.
Brandon Desmyter is a soccer player at DeWitt High School in Michigan. He has been All-League, All-District, and All-State, and will be team captain in 2015.
Alison Lohman's birth name is Alison Marion Lohman.
Alison Cronin's birth name is Alison Ames.
Alison Levine goes by Alison Hartwick Levine.
Alison Corino goes by Alison Danger.
Alison = 'Alikoni
Taylor Swift's middle name is Alison and by the way, she is my favorite singer!
Alison Sudol's birth name is Alison Sudol.
Alison Stern's birth name is Berns, Alison.
Alison Knowles has written: 'Untitled by Alison Knowles'
Alison Sweeney was born on September 19, 1976.