Poetry analysis in junior high tends to try to get the pupil to engage with the piece (ie present their own interpretation of the message, mood and language techniques) but a more advanced critical analysis involves looking at the poem more objectively, ideally comparing it with others by the same poet and his/her contemporaries and past works in terms of several qualities.
Relevant features to compare are style, structure, tone,voice,register (the author's vocabulary) rhyme scheme, metre,exposition and effectiveness (the idea of affect - does the message get across, whether it is clear or deliberately oblique.)
After completing this, in terms of a close reading of the poem, you will also need to read other works by the same poet and engage with arguments with critics, both of the time and contemporary. Be sure to cite these carefully, and to use examples and quotes.
Conclude your critique by summarising what you have found, and engaging with the debate about the poet. Do you agree with positions of some critics, but not with others? Be prepared to say why in your conclusion, but be careful n ot to repeat the whole essay again ,in doing so. Quotes are not usually appropriate for the concluding paragraph.