They are common.
I and me are pronouns, not nouns. They replace proper nouns like names for people.
I is the nominative first-person pronoun, and me is the objective first-person pronoun. This basically means that "I" is useful as the subject of a sentence: "I took a picture."
...while "me" is useful as the object: "Atiya took a picture of me."
If you're asking so you know about capitalization:
I must always be capitalized, but me only needs to be capitalized if it is the first word in a sentence.