Who are the origin of Hebrew people and the land ? Genesis 40:15

Abraham is the patriarch of the Hebrew people. All the other Hebrew people are descended from him, or married into their group, or were attached to them as servants.

Abraham had 318 trained servants accompany him to rescue his brother Lot who was kidnapped in Genesis 14. This site (https://www.studylight.org/language-studies/difficult-sayings.html?article=509) claims that Abraham had a retinue of about 2,000 people, including his children and servants.

The only land that Abraham owned was what he purchased as a grave site for his wife. He was a nomad, but often stayed among the Canaanites.

There is a short but definitive article published in the Journal of Evangelical Theological Society in 2012 What's in a Name? An Examination of the Usage of the term "Hebrew" in the Old Testament written by an OT Professor Dr. Matt Akers which describes the difference between "Hebrew" and "Israel" in the OT, and how both Hebrew and Israel "finally became a racial designation for God's covenant people."

After introducing the pliability of ethnonyms (II), Eber's relationship to the Hebrews (III), and the usage of HABIRU (cognate of Hebrew) in extant ancient literature (IV) the article analyzed Old Testament's usage of "Hebrew" to discern what the author wanted to distinguish from "Israel" (V).

Here's the conclusion (VI):

After analyzing the above evidence, several observations may be made. First, “Hebrew” and Habiru certainly are cognates. Both words, second, possess nearly identical shades of meaning. The terms were ethnic designations that over time began to denote immigrants, warriors, and servants. Third, one of the earliest references to the Habiru hails from Mesopotamia, the region from which God called Abram the Hebrew. The shared geography cannot be a coincidence.

For these reasons, the populace of the ancient Near East would have regarded Abraham, Isaac, Jacob, and Joseph as Habiru because of their semi-nomadic sojourner lifestyle. It does not follow, however, that they would have considered the Habiru to be Israelites as the lineage of Eber establishes. Simply put, in the early OT era, “Hebrew” refers to any descendant of Eber, while “Israelite” pertains only to the branch of Eber’s family that Jacob sired. Only later in OT history did “Hebrew” finally become a racial designation for God’s covenant people.

Another journal article The Habiru and the Hebrews: From a Social Class to an Ethnic Group published in Volume 7 Issue 3 of the Jewish Bible Quarterly provides a similar conclusion. The article provides additional details on the archaeological discoveries relied on by the JETS article.

Concluding paragraph from the article (emphasis mine):

All the evidence from archaeological discoveries to date seems to point to the conclusion that, sociologically, the Hebrews were in fact Habiru, although not all Habiru were Hebrews. It could well be that the word עברי (Hebrew) was originally only a sociological designation, indicating status or class - in which case the words Hebrew and Habiru are synonymous. The fact that in the later Books of the Bible and in its usage in post-biblical times, the word Hebrew has been used as an ethnic designation simply means that the original meaning of the word has been changed. With the eventual disappearance of the Habiru, etymological explanations of the term "Hebrew" such as mentioned at the beginning of this article, were inevitable. In the absence of archaeological evidence until comparatively recent times, the Pentateuch itself was the oldest record extant from which an explanation could be sought. And so the term "Hebrew" ultimately became equivalent to the term "Jew" as in the Book of Jeremiah where the prophet proclaims:

that every man should let his man-servant, and every man his maidservant being a Hebrew man or a Hebrew woman. go free; that none should make bondmen of them, even of a Jew his brother ... " (Jeremiah 34:9)

Nonetheless this cannot detract from the clear indications which exist that the origins of the Hebrews are as Habiru.