Why is Jesus said to be pre-eminent of creation in Colossians 1:15 and not the Father and the Spirit also?

1) Why is Jesus said to be pre-eminent of creation

Literally nonsense.

If you don't know a word

please look it up in the dictionary before you use it.

2) If the trinity is true why didn’t Paul state God is Firstborn of creation and not just 1 person of the trinity.

Because it was just one Divine Person of the trinity that experienced being born.

3) Also who is God’s real Firstborn son or it’s not Jesus?

Jesus is God's only-begotten son.

4) Where does the Bible state Jesus is Jehovah?

Not directly

but definitely indirectly.

The author of Hebrews

teaches us that Heb 1:10-12 describes Jesus.

The author of Psalm 102

(see vv 22-27)

teaches us that very same passage describes (explicitly) YHWH ("the LORD", "Jehovah") (and again explicitly) God.

P.S. You wrote

>> Again USER you didn’t show me where the father and spirit is also firstborn of creation  <<

You didn't ask me to show that

and if you had

I wouldn't make any attempt

because

they are not.

As I pointed out:

"...it was just one Divine Person of the trinity that experienced being born..."

Because according to St. Paul, only the Father is God.  Jesus is only one of the Lords, or lesser divine beings.  The New Testament clearly states that Jesus Christ is Jehovah incarnate, the creation and begotten son of God (who is Elohim).

1.  Supremacy in creation (agency, v.15-17, (Heb. 1:2, John 1:3)  2.  Supremacy in redemption, vv. 18-20.  "Firstborn"  has rights in priority, preeminence, and sovereignty, vv. 16-18.

Jesus is eternally begotten of God the Father, of one and the same divine, almighty, godly "stuff". It was the Father's idea to create all things through his divine son, Jesus. 

Cult teaching that’s why. Jesus is not Jehovah but a copy or exact REPRESENTATION of his being. Hebrew 1:3 a copy is not the original