Did Israel Steal Palestinian Land?

Like the rest of human history, this has become a shit show.

Thank you. I keep seeing posts where people claim Israel stole land from Palestine...

Yes. It dis, and is still doing so.
The Haganah and Irgun declared Israel a nation in May 48 because they wanted to accept the UN partition draft proposed in December 47 instead of negotiate. They land intended as Palestinian territory was not contiguous, because Israel intended and stated that it wanted those territories to border the nearby nations, who Israel intended to have annex them. That refusal to negotiate also resulted in the assassination by the same terrorist gangs (Stern and Irgun) of County Bernadette the Partition's chief negotiator who was in country at the time. There was no forward movement with negotiating after that that made in any headway, since then (September 48). Fast forward, after the June War, 67, Israel has tried to convince the world there is not partition, that all the territory belongs to Israel. It did return some of Golan Heights - and Sinai which was not ever part of the partition. The UN has always continued to work towards negotiating and settling the partition of territories, and has never recognized the whole of Palestine is Israel, as Israel wants to claim. That means that the settlements the governent of Israel builds in Palestinian Territories (based on the unnegotiated draft partition) are illegal according the the Geneva Conventions about how an occupying nation is obligated to provide for people in the territory it occupies. Hasn't stopped Israel from "annexing" Palestinian territory for "Jewish only" settlements; building roads that only Israelis can travel on. And the settlers, have raided, harmed, killed Palestinian on other own land, nearby without any provocation - and have uprooted hundreds of year old olive trees, and destroyed everything they could in the field, to try to convince the Palestinians to leave.
And how about is Israel committing genocide?
Anyone literate can read the Geneva Conventions that define genocide as a result of the Nurenberg trials for the purpose of "never again" a Holocaust. Yet, how many genocides have there been since that time . . . .several in Africa, former Yugoslavia, the Uighers in China . . . something in S.E. Asia . . . and the ongoing one the government of Israel has been perpetrating since 1948 (which started earlier when the Haganah and Irgun told Palestinians they would be killed if they did not leave the territory in the partition draft that was designated as Israeli territory. Then they proceeded to make good on that "promise" by massacreing entire small villages of Palestinian people. After the horrendous Deir Yassin massacre there was an Exodus of Palestinian refugees - the Nakbah had stared - and it has never ended, only become worse, slowly over time since the June War when the government of Israel decided if it pretended the entirety of Palestine was Israel, it would eventually be believed as if "THE LAW" agreed upon to which Israel was also signatory, did not matter. It is only Israel to whom it does not matter.