First of all, go here -- http://nfs.sparknotes.com/ -- and find Macbeth and the act and scene you need. Then you will be able to read the original 16th century English on the left and modern-day English on the right. The right column will help you with MEANING, but not with poetic elements; use the left column for Shakespeare's own language which you are to discuss in your paper.
THEN read through these webpages for instructions about how to read and how to explicate any poetry, whether it's in play form or not.
Once you have read through all this and begin to follow the directions on one of the three poetry explication webpages, let me know if you have more questions.