You're saying that as though being there first was the deciding factor in who should be there now?
I'm not, but it helps.
Of course there were people there before the Jews arrived, Canaanites, Moabites, Philistines, etc, but these people have long since become assimilated into other groups or disappeared from history completely, as distinct and identifiable groups. The Arabs, on the other, of which the current Palestinians claim to be a part, didn't really arrive in Israel until 635CE when the Moslem armies took Jerusalem. The Arab people come from the south of the Arabian Peninsula and spread as nomads and traders. Although the Arabs and Jews are both Semitic people, as are the Hashemites, Syrians, Lebanese, etc, the Arabs have a lot less in common with the other sub-groups.
In digging about I have found reference to a man called Omni from 925BCE, he is named as King of Israel on an Egyptian stelae. And while we are discussing this the ancient Egytians were not Arabic people either, I have read comment claiming the Arabs built the pyramids.