The Start of Revelation - The Vision of the Woman with 12 Stars

Chronologically in time, this story of the Woman with 12 Stars is the start of everything that is happening in the book of Revelation. Chronologically it precedes the Vision of the Two Prophets, even thought the order in which it appears in Revelation is reversed.
Let's discuss the text.

Revelation 12:1 Then a great sign appeared in heaven: a woman clothed with the sun, with the moon under her feet and a crown of twelve stars on her head.

This reminds of the dream of Joseph where the sun and the moon and eleven stars were bowing down for him. These where his father, mother and brothers. This is an image of the nation of Israel with the twelve tribes. But we might even say that this is the True Israel, meaning that part of Israel that respects and obeys God, hence the sun that is upon her.

2 She was pregnant, and she cried out because she was in labor, in pain from giving birth.

This refers to the Messiah that is about to come out of Israel.

3 Then another sign appeared in heaven: it was a great fiery red dragon, with seven heads and ten horns, and seven royal crowns on his heads. 4 His tail swept down a third of heaven’s stars and threw them to the earth. The dragon stood in front of the woman who was about to give birth so that when she gave birth, he might devour her child.

In Revelation 13, 17 and 20 we can learn more about this dragon and similar beasts. They represent the devil and the Roman Empire that is an instrument of the devil. The devil wants to obstruct Gods plans and tried to kill the child when it was born by means of Herod who killed all two year old children in the neighborhood of Bethlehem (see Matthew 2:16).

5 She gave birth to a son, a male child who is to rule all the nations with an iron rod. Her child was snatched up to God and his throne.

The vision fast forwards through the life of Jesus up till he ascends to heaven.

6 Then the woman fled into the desert, where God has prepared a place for her. There she will be taken care of for one thousand two hundred sixty days.

The woman has to flee into the desert, representing that the people of Israel can no longer live in their country. But she is protected there for 1260 prophetic days. This is the same (type of) period as in the Vision of the Two Prophets and they start at the same time as well (the destruction of the temple).

7 Then there was war in heaven: Michael and his angels fought the dragon. The dragon and his angels fought back, 8 but they did not prevail, and there was no longer any place for them in heaven. 9 So the great dragon was thrown down. The old snake, who is called the devil and Satan, the deceiver of the whole world, was thrown down to the earth; and his angels were thrown down with him.

10 Then I heard a loud voice in heaven say,
"Now the salvation and power and kingdom of our God,
and the authority of his Christ have come.
The accuser of our brothers and sisters,
who accuses them day and night before our God,
has been thrown down.
11 They gained the victory over him on account of the blood of the Lamb
and the word of their witness.
Love for their own lives didn’t make them afraid to die.
12 Therefore, rejoice, you heavens and you who dwell in them.
But oh! The horror for the earth and sea!
The devil has come down to you with great rage,
for he knows that he only has a short time."

You can look at it like this: the devil keeps records of the sins of every person and has access to heaven to remind God that those people are his (see the book of Job, 1st chapter). Now that the innocent blood of the Messiah has flown as a substitution, all these charges have been erased. The devil can be denied his access to heaven now, but he did not leave without a fight.

13 When the dragon saw that he had been thrown down to the earth, he chased the woman who had given birth to the male child. 14 But the woman was given the two wings of the great eagle so that she could fly to her place in the desert. There she would be taken care of—out of the snake’s reach—for a time and times and half a time.

It is repeated and specified that the woman (the True Israel) will be safe in the desert for 3,5 times (which is 42 months or 1260 days).

15 Then from his mouth the snake poured a river of water after the woman so that the river would sweep her away. 16 But the earth helped the woman. The earth opened its mouth and swallowed the river that the dragon poured out of his mouth. 17 So the dragon was furious with the woman, and he went off to make war on the rest of her children, on those who keep God’s commandments and hold firmly to the witness of Jesus.

The river of water is an attempt to kill the woman. This can be linked to the destruction of Jerusalem during the Judea-Roman war.
The earth does not have always have to be the globe. It can also mean a country. Similar as the word land can mean a field in our language as well as a country. That the earth swallowed the stream thus can be understood as: the people of Israel taking the blow of the dragon, so the True Israel can escape.
Jesus clearly told his people to stay away from Jerusalem, because it would be destroyed (see Luke 21). Also he told his people to not take up the sword against the Romans (when Peter cut off the ear of one of them, Matthew 26:51-52). It means they did not fight the Romans in Jerusalem and survived the massacre.

Now the Vision of the Two Prophets continues where this Vision stops, with the 1260 prophetical days referring to the same period in both.