A first person form is a form that must refer to the producer (speaker/signer) of the current utterance or to a group of people including the producer.
first person pronoun (CXN) = a personal pronoun used for contextual reference to a person in their role as speaker. The term is conventionally used also for a pronoun referring to a group of persons, one of whom is the speaker. Example: I and we are first person pronouns, the former referring to the speaker and the latter to a group including the speaker. (Section 3.1.1)