To dream that you see some kind of the gates means that you are about to enter the new chapter of your life. If the gates are opened, you are entering into this new phase being strong and confident about yourself. The dream could also show that you are getting yourself into unknown situations or events. The gates that are closed in your dream shows that you are not ready to start the new life, or do not feel confident enough to face the unknowingness.
Read more about dreaming of Gate in other dream meanings interpretations.