Verified answer

Your permanent residency is not important, your passport is. As you are a Vietnamese citizen, you will need to apply for a Schengen Visa before you leave the US. You don't say which countries you want to visit in Europe, but you will need to apply to the Embassy of the country in which you will be spening the most time.

Hi there! You still need to provide a passport so that you can visit a certain country like Europe. That's the protocol of a a certain Immigration or travel agency whenever you visit a certain country. Just Apply for that.