Is a common noun same as a pronoun?

No, they are not the same.A noun is a Word for a person, place, or thing; a noun functions as the subject of a sentence or clause, or the object of a verb or a preposition.

A pronoun is a Word that takes the place of a noun as the subject of a sentence or a clause, or the object of a verb or a preposition.

Examples:

Noun subject of sentence: Aunt Jane made cookies for Jack and Jill.

Pronoun subject of clause: The cookies that she made are for Jack and Jill.

Noun direct object of verb: Aunt Jane made cookies for Jack and Jill.

Pronoun object of preposition: Aunt Jane made cookies for them.