I beheld till the thrones were cast down, and the Ancient of days(God) did sit, whose garment was white as snow, and the hair of his head like the pure wool: his throne was like the fiery flame, and his wheels as burning fire. Daniel 7:9

The term “Ancient of Days” was used by Daniel to describe God. Why because God is everlasting. The vison he sees is clearly God sitting on the throne as described in Revelations 1:14-15

However I suggest you clearly read Daniel 7:9 and Revelations 1:14 and notice there descriptions are identical further proving the Trinity between God the Father and Son Jesus Christ

A fiery stream issued and came forth from before him: thousand thousands ministered unto him, and ten thousand times ten thousand stood before him: the judgment was set, and the books were opened. Daniel 7:10

Another seen that is clearly describe in Revelations 5:11, as thousands of Angels surround God on his throne. And the book being opened clearly is the Book of Life (Revelations 20:15)

Daniels vision is clearly of judgement day when we will all stand before our Lord Jesus and account for our lives.

I beheld then because of the voice of the great words which the horn spake: I beheld even till the beast (Satan) was slain, and his body destroyed, and given to the burning flame. Daniel 7:11

The beast is Satan, and this event is when Jesus destroys Satan and cast him into Hell. This event is also described in Revelations 19:20

As concerning the rest of the beasts, they had their dominion taken away: yet their lives were prolonged for a season and time. Daniel 7:12

The Kingdom of Satan will be destroyed and all power that Satan and his followers have right now will be gone.

I saw in the night visions, and, behold, one like the Son of man(Jesus) came with the clouds of heaven, and came to the Ancient of days (God), and they brought him near before him. Daniel 7:13

The same even as clearly described in Matthew 24:30, as Jesus is The Son of Man, he is the Messiah and giving all authority by God his Father.

And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion is an everlasting dominion, which shall not pass away, and his kingdom that which shall not be destroyed. Daniel 7:14

Jesus is King of King and Lord of Lords (Revelations 19:16) he will rule all nations, governments will rest on his shoulders (Isaiah 9:6) He will rule with a rod of iron (Revelations 2:27) and Gods kingdom will rule forever(Hebrews 1:8) in Jesus Name Amen