In your defense, Catholic schools have deeply failed at catechizing properly, and in regards to the book of Revelation specifically, I would argue that most Catholics in general probably do not understand this book. And in defense of those Catholics, the book of Revelation is an incredibly difficult book to read and understand. The book of Revelation has many intertwining elements in it and heavily relies on symbolism.
(Which makes it my favorite).
I'd like to clarify a bit; most of the book of Revelation has already happened, and it's especially important to keep in mind the historical context in which it was written and the events that were happening at that point in time.
Some background info is necessary here; the book of Revelation is thought to might have been written by the Apostle John (as in, John who wrote the fourth gospel), but it is more likely to have been one of John's disciples. At the time it was most likely written around 81-96 A.D. when Christians were being heavily persecuted by the Roman Empire. This is part of the reason why Revelation was veiled with symbolic language; so that the Romans wouldn't be able to understand the message.
So at that point in history, this book had a fairly different impact and meaning for the early Christians than what it means for us today. The early Christians more than likely thought that Jesus' Second Coming was going to happen in their lifetime, but considering a few decades had passed since He ascended, and the fact they were being martyred, persecuted, tortured and imprisoned under the empire, it isn't a surprise that those Christians were probably second-guessing their faith and trust in God and were losing hope. They were in danger of sacrificing their faith via conversion to paganism if it meant escaping torture and death.
Thus, the book of Revelation, or sometimes called the Apocalypse, was written as a way to encourage Christians to remain steadfast in their faith and to persevere even under threat of the Romans. The author could not just write "Do not give in to the Romans. Remain faithful to Christ, Who is true God and King. Resist the Roman empire" - but what he could do is write about this time of persecution using symbolic language and code and references to a greater cosmological struggle.
(Which is one of the reasons that the book was written and still stands to be relevant for us today; Revelation tells us that no matter how awful the world is, no matter the crisis and struggles we face, that we should keep our eyes on the much bigger spiritual picture. The fact that this all can still apply to us today in modern times is why it was put into the bible, because it is the Living Word of God).
With all of that in mind, the book of Revelation can be looked at as almost a summary of our Salvation. John writes about his visions in which he sees Christ, where he was transported to Heaven and witnesses beautiful acts of worship- he is describing our beliefs and our very own Catholic Mass.
"Each of the elders held a harp and gold bowls filled with incense, which are the prayers of the holy ones" (Rev. 5:8) - we still practice this! That incense at Mass is not just for the smells and bells, but because the smoke that comes from the burning of incense is symbolic of our prayers being lifted to Heaven.
"Then one of the elders spoke up and said to me, "Who are these wearing white robes, and where did they come from?" I said to him, "My lord, you are the one who knows." He said to me, "These are the ones who have survived the time of great distress; they have washed their robes and made them white in the blood of the Lamb" (Rev. 7:13-14) - this easily describes two of our beliefs in one; the saints in Heaven are clothed in white (the color white being symbolic of grace), and can also refer to the sacrament of Baptism, where we often clothe the newly baptized in white garments to symbolize the washing away of Original Sin and being brought into the Church.
"A great sign appeared in the sky, a woman clothed with the sun, with the moon under her feet, and on her head a crown of twelve stars. She was with child and wailed aloud in pain as she labored to give birth. Then another sign appeared in the sky; it was a huge red dragon, with seven heads and ten horns, and on its heads were seven diadems. Its tail swept away a third of the stars in the sky and hurled them down to the earth. Then the dragon stood before the woman about to give birth, to devour her child when she gave birth. She gave birth to a son, a male child, destined to rule all the nations with an iron rod. Her child was caught up to God and his throne. The woman herself fled into the desert where she had a place prepared by God, that there she might be taken care of for twelve hundred and sixty days." (Rev. 12:1-6).
This chapter goes on to describe a great spiritual struggle and battle between the angels, naming the archangel Michael specifically, and with the dragon and his (fallen) angels. This chapter is specifically speaking to events that have already taken place; the crowned woman clothed in sun with the moon under her feet is the Blessed Virgin Mary! Crowned because she is the Mother of Jesus, who is King, and she is our Queen of Heaven and Earth. Clothed in the sun with the moon under her feet because she is a reflection of Christ; the moon reflects the sun's light. Stars were often symbolic of the communities of the Church at that time. The dragon, in regards to the woman, is symbolic of King Herod who persecuted the infant Jesus. Mary and her family had fled from Bethlehem to Egypt; the desert, where if you remember in the book of Exodus, is where Moses first led the Hebrews out of to find the Promised Land.
When we come to talk about the cosmological struggle between the angels and Satan, this has already happened. If read further, scripture reads that Satan and his fallen angels did not prevail in that battle and were casted out from Heaven because there was no place for them, so they came to earth. Once they made this decision at the very beginning of time (or their concept of time), it was permanent, and can never be changed or repented because angels are believed to have the knowledge of that choice and its consequences.
It goes on to describe how Satan would pursue the child of that woman, which is reflected in the four gospels written about Jesus' life and ministry. It also talks about how Satan failed to wage war against the child, so Satan instead went off to pursue the woman's other offspring- us. We all often fall into this great spiritual struggle of temptations, sin, and tests and trials of faith. In the context of when this was written, John was more than likely speaking of his concern for the Christians who were casting their faith in Christ aside due to persecution and using Satan as a literary metaphor for the Romans.
Now, the book of Revelation does speak to future events that we are still expecting. The Second Coming of Christ, the Last Judgment, these events have yet to take place in our concept of time. We know not the day or hour. But we do know that this earth, in all its glory and chaos, is temporary. War and famine are temporary. All of our materials are temporary. Even our fleeting emotions are temporary. We live in a temporal place, and it is easy to lose sight of an eternal Heaven on this side of it.
That is the point of the book of Revelation. It isn't meant to scare us into a doomsday mindset. It isn't a book of conspiracy or superstition. This is why I said that Revelation is about giving people hope and consolation; this is why it is still a relevant piece of literature today. Because the main message still sincerely applies to us. There is Something much bigger than the things we see and experience and struggle with here, and that Something is worth struggling for.
"He will wipe every tear from their eyes, and there shall be no more death or mourning, wailing or pain, for the old order has passed away." (Rev. 21:4).
