Is lady or lunch lady a proper noun in the following sentence?

The lunch lady told me that I had to pay three dollars.

I would hyphenate lunch-lady. That is the correct term to indicate which person told you that.

Okay, so if I hyphenate it will it make it a proper noun?

No. Lunch lady is a common noun.

In the sentence "The lunch lady told me that I had to pay three dollars," the term "lunch lady" is not a proper noun. It is a common noun because it refers to a generic title or job role, rather than a specific person. Proper nouns are used to name specific people, places, or things and are capitalized, while common nouns are more general and do not require capitalization. To determine if a noun is proper or common, you can ask yourself if it refers to a specific individual or entity. If it does, it is likely a proper noun and should be capitalized.