Understanding Daniel's Prophecy

In verse 9 it talks of the Ancient One. Would I be correct to say this is Hashem? Who do the lion, bear, leopard and “beast” represent? In verse 13 -14 it now adds a "son of man". Who is it talking about?

Yes, “the Ancient One” is a nickname for Hashem, and verses 13-14 refer to the 5th and final kingdom, that of Israel (see v. 27). Daniel prophecizes that after Babylon, Persia, Greece, and Rome (including all of the European Christian empires), Hashem will bring back Israel to be the superpower, as in the days of David and Shlomo, through the Mashiach (Messiah) from the House of David. He and the Kingdom of Israel are referred to as the “son of man”, as opposed to the aforementioned animalistic, cruel and imperialistic kingdoms who were likened respectively to a lion, bear, leopard and “beast” (v. 3-8, see commentaries why), the kingdom of Israel will be a human (=humane) kingdom, leading the world to be a better and more moral place (Universal Nationalism). Our rabbis taught us that the transition will be gradual, starting as a small, secular and democratic Jewish State, out of which will grow the strong, influential, religious and universally respected sovereignty of Mashiach (Maharal, Gvurot Hashem ch. 18; Micha 4, 8 and the Malbim, there).