The people who were there at the time would NOT have been what we'd considered Palestinians today, though. Same general region, but somewhat different ethnicity.
Palestinians are Arabs. And Arabs didn't enter the Levant in large numbers until the 630s AD/CE when the freshly Islamized Arabs came out of Arabia and conquered it from the Byzantines (Romans).
The Siege of Jerusalem was from 636-637 AD/CE and was the finally conquest of the Islamic forces, after which you start to see large scale Arab settlement in the Holy Land.
Prior to that the native inhabitants were Israelites- Jews- who began as one of the Canaanite tribes. Putting dates to Exodus and assuming it's mostly accurate can be dangerous, so let's just rely on archeology.
It appears as if Israelites, the ancestors of Jews, emerged as one of the many Canaanite tribes. The Canaanites had a pantheon as most ancient groups did and each group would have had its own patron deity in the pantheon. Israel got Y-hweh, the storm god. And indeed the earliest versions of pre-codified Old Testament scripture confirm this by saying of the nations Y-hweh was given "Jacob and his inheritance," Jacob being the original "Israel."
There was some sort of societal upheaval in the Canaanite world though and either gradually or relatively suddenly, we don't know specifically, Israel began to subsume the other Canaanite tribes and Y-hweh was promoted to chief god, assuming the names and powers of the old chief god, El, which is why both "el" and the plural "elohim" are both titles for Y-hweh and generic terms for deities in the Bible's original Hebrew.
This Israelite subsuming of Canaanite society is likely what the Biblical story of Joshua conquering Jericho alludes to.
Point is the Canaanites were closer related to modern day Jews and Phoenicians than they were Arabs.
All of them are semitic groups of course, but the Biblical story of Jericho predates Arabs' arrival in the area by thousands of years and is likely a poetic retelling of Israelite ascendency within the Canaanite tribal framework.
I think Abraham, Isaac, and Jacob were actually in Palestine after the great Flood and actually formed the 12 tribes of Israel there. They migrated to Egypt to escape the famine in Palestine. So it looks like the Israelites were originally there to begin with.
The Great Flood, if it happened at all, is likely an ancestral memory dating back to when the proto-Israelites were still living in Mesopotamia given that the Biblical flood myth mirrors Mesopotamian flood myths.
According to the Bible the Twelve Tribes of Israel were founded by the twelve sons of Jacob, who was anointed as "Israel" when G-d was suitably impressed with him.
If you follow the Bible's genealogy he's Isaac's son and Abraham's grandson. With Abraham taking his family from Mesopotamia to the Holy Land likely a retelling of the original exodus of proto-Israelites from Ur to the Levant after they split with the Mesopotamians.
