Heb 7:1-2

For this Melchizedek, king of Salem, priest of the Most High God, who met Abraham as he was returning from the slaughter of the kings and blessed him,

to whom also Abraham apportioned a tenth part of all the spoils, was first of all, by the translation of his name, king of righteousness, and then also king of Salem, which is king of peace.

Hebrews clarifies that it was Abram (Abraham) who gave the tenth to Melchizedek.
The Genesis passage could be open to interpretation.
Hebrews makes clear what occurred.

We also learn that Melchizedek was not only the King of Salem and a priest of the Most High God.
He was as his name is translated - “king of righteousness”.
Also, King of Salem means King of Peace.

We know nothing else of Melchizedek from Genesis.

Here is how Hebrews describes it…and the purpose of mentioning him…

Heb 7:3
Without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, he remains a priest perpetually.

Apparently Melchizedek was a real, physical person.
We do not know who his father, mother were.
His genealogy is not revealed.
We know not when he was born nor when he died. (Obviously, he was born and died.)

What is being said through Melchizedek?

We will see more.

For now, he was made like the Son of God.
He was a priest of the Most High God perpetually.
Long before the priesthood was established.

Long before the fulfillment of what Melchizedek foreshadowed…