Plot hole: The entire plot revolves around the First Order chasing the ships, waiting for the Resistance to run out of fuel. They could have easily destroyed the Resistance's fleet by sending a Star Destroyer or two around to cut them off from the other side and blast them into oblivion.
Plot hole: Luke deliberately says he does not want to be found and came to Ach-To to die in The Last Jedi, but The Force Awakens is all about finding a map to Luke Skywalker. Why would Luke leave a map when he never wanted to be found?
Plot hole: By having Admiral Holdo perform her infamous hyperspace ramming stunt, Rian Johnson created a continuity problem with the rest of the Star Wars universe. Since this maneuver was successful, every space battle before and since should only include a droid piloting spacecraft ramming enemy bases through hyperspace. This tactic would have been more cost effective and less risky than full on space battles seen in previous films. This tactic would no doubt have been tried in a universe filled with space battles often with disposable troops on both sides, such as in the Clone Wars. The Death Star did not need a successful trench run to be destroyed, just an X-wing with a droid ramming it at hyperspeed.
Other mistake: Maz Kanata's message is somehow not intercepted by the First Order. It is also projected from various angles and follows her around during her shootout, making one question who is filming the call in the first place?
Other mistake: During the big battle between Kylo Ren and Luke Skywalker (as a force projection), Luke appears with his blue lightsaber. While I assume that a force projection probably appear any way he wants, and he did choose to look younger, Luke had lost his blue lightsaber decades ago during his battle with Vader on Bespin Cloud City. He had already built a new green one by the time Return of the Jedi started, so why would he appear with the blue one? It should have immediately given away to Kylo that he was a force projection and not the real Luke.