A personal pronoun is a pronoun that takes the place of a noun for a specific person or thing.
Yes, “we” is a personal pronoun, a word that takes the place of a noun (name) for specific people (the person speaking and one or more other people).
Some nouns sound like they should be plural but are actually singular. If a noun needs a singular verb, then it should also get a singular pronoun.
Possessive pronouns show ownership: That’s my book.
Subjective and objective pronouns are simply pronouns that occur in either the subject or the object of the sentence. Subjective pronouns tell us who or what the sentence is about. Objective pronouns receive the action in the sentence.
The pronoun I in this sentence is actually incorrect because it appears in the object of the sentence. The sentence should read something like this: