Depends on what word is underlined.
<em>Maria </em>is a noun, (<em>will</em>) <em>show </em>is a verb, <em>us </em>is a pronoun, <em>the </em>is a determiner, <em>pictures </em>is a noun, <em>she </em>is a pronoun, <em>took </em>is a verb, <em>while </em>is an adverb, <em>on </em>is a preposition, <em>vacation </em>is a noun.
The most common are 1st and 3rd person. 1st person is when you tell a story from your point of view, using the pronouns "I or we." And 3rd person is from an outside point of view, using the pronouns "he, she, and they." 2nd person isn't very common because it uses the pronoun "you," and makes the audience a character in the story. Hope this helps!
A subordinate idea in the sentence is the part of the sentence that does not convey a complete idea or thought and needs the main sentence to complete its message. The subordinate idea in the given sentence above is "After we found the classroom". This is introduced by the subordinating conjunction "after".