"God-Son" in the book of Revelation?

I've been ask this type of question in the past but in another form. "How do you distinguish which person the Bible is referring to throughout the scriptures when the three distinguishing titles of the Godhead are not used?"

For example, "God said let us make man in Our image, according to Our likeness etc." (Genesis 1:26.) Is "God" all three, and who is "His" referring to? There are so many scriptures that only use "Lord, God" and many other titles referring to God. God said, My glory I will not give to another...Is this all three speaking or is only one of the three?"

Where no distinction is made, it is obviously unnecessary to make a distinction. The persons of the Trinity are persons in relation to each other, any one of the persons in relation to us is simply God. In that there is only one God, if God says to us His glory He will not give to another, that is because there is only One God.

Since you brought up Revelation 1:8 it says, "the Lord God." We can deduce this is referring to Jesus Christ based on the context/the surrounding verses. At Revelation 1:17 Jesus says, "Do not be afraid; I am the first and the last."

Now look at what Isaiah 44:6 states, "Thus says the Lord, the King of Israel And his Redeemer, the Lord of hosts; I am the first and I am the last, And there is no God besides Me." Please notice the verse does not "specifically" identify a person of the Godhead, it just says "the Lord."

Lastly, you said this: "Father is not Alpha and Omega, is he not all powerful? The Holy Spirit is not the Alpha and the Omega, Is he not all powerful?" Yes, all three persons of the Trinity are "all powerful." Please read the following. https://www.blueletterbible.org/faq/don_stewart/don_stewart_328.cfm

Sticking to your query about the use of the title, "Alpha and Omega" in the book of the Revelation, these suggestions are offered to you, in the hope that it will bring a little clarity to a very complex matter.

The first use of that title is with someone suddenly speaking after the apostle John's introduction. It is in ch.1 vs. 8 as you say:

"I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty."

John then speaks over the next two verses, followed by him hearing a great voice behind him saying:

"I am Alpha and Omega, the first and the last: and what thou see write in a book..." (vs.11).

John turned to look behind him and saw the glorified Jesus Christ. The vision was so spectacular and heavenly, John fell at the feet of this One, as though dead. This One laid his right hand on John's shoulder and assured him:

"Fear not. I am the first and the last. I am he that liveth and was dead, and behold I am alive for evermore; Amen; and have the keys of hell and of death. Write the things which thou hast seen..." (vss. 17-19)

The next time the title is used, it's at the end of the vision where the speaker says:

"And behold, I come quickly; and my reward is with me, to give every man according as his work shall be. I am Alpha and Omega, the beginning and the end, the first and the last... I Jesus have sent my angel to you to testify unto you these things in the churches... And the Spirit and the bride say 'Come'... He which testifieth these things sayeth, Surely I come quickly. Amen. Even so, come Lord Jesus." (Ch. 21, vss.12-20)

Just read over those instances and think about who is saying what. But if you are new to the Bible, you are not going to get it until you spot the role of the Son of God and the Holy Spirit throughout the New Testament. The book of the Revelation helps clarify their respective roles in the Godhead in heaven; the resurrected Christ is shown as standing in the middle of the one throne of God in heaven, all heaven's population worshipping him who sits on throne, and the Lamb [Christ] at the center of the throne, the seven-fold Spirit of God surrounding that throne also being worshipped.

Yet this is what is revealed at the end of the Bible. The need is to start at the beginning, and John's gospel account does that, so I recommend you start at John ch. 1 vs 1 before hoping to make any sense out of John's last written account, the Revelation.