just fer fun

Are we speaking of the first mention of the literal name Christ, or the first mention of the messiah in general?
You could go back to genesis 3, it's pretty broad, but a general idea is that the seed of the woman is the Messiah, like I said though, it's a bit out there, but it fits

And I will put enmity between you and the woman, and between your seed and her Seed; He shall bruise your head, and you shall bruise His heel (Genesis 3:15).
Yes it is Genesis 1:1

4th word

In1 the2 beginning3 God4

This hasn't anything to do with Hebrew language, but because the next word is CREATED.

In the beginning God created

In John 1:3 we see Christ is said to be the creator of all.

All things were made by him; and without him was not any thing made that was made. - John 1:3 KJB

Also in Hebrews...

Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds
- Hebrews 1:2 KJB