This video presents the historic background to the Israli-Palestinian conflict. If details in this video do not fit with what you have heard about the conflict it can be explained by the years of Arab propaganda against Israel.
There were Arabs in British Mandatory Palestine before the Jewish nationalist movement was founded in the late 19th century, but they considered this territory as part of Syria. No one claimed this territory belonged to a people called “Palestinians” until the Zionist movement began to inhabit the land.
Here are the links to the Palestinian National Charters of 1964 and 1968 in the UN website (read article 24 before and after the 6 day war, 1967).
The different names that they gave to Israel:
Pelesheth – Philistia – Filisteos—Filistea / Aelia Capitolina – Palestina / Judea de Palestina