A noun is a word that describes a person, place, or thing. "Nora" is a noun because it is the name of a person. "The beach" is a noun because it is a place. "The beach" can also be a thing.
There are two types of nouns: proper and common. Proper nouns begin with a capital letter because they name a specific person, place, or thing. "Nora" is a proper noun because it is the name of the girl. Common nouns do not begin with a capital letter. "The beach" is a common noun.
A pronoun is a word that can be used in the place of a noun. Instead of saying, "Nora is at the beach", we could say, "She is at the beach". "She" is the pronoun.