In Act I, as Macbeth is coming back to report to King Duncan after the war, Three witch sisters appear and tell him he will be Thane of Cawdor and even king in the future. Macbeth is quick to believe it.
Get out of here ghost!
His wife Lady Macbeth hears the news, and since the first prediction already came true (He is now Thane of Cawdor), she wants Macbeth to kill King Duncan and claim title as king. She challenges his title of a man whem he starts doubting.
God in heaven, bring Macbeth face to face with me soon so I can fight him!
Come, our army is ready.
In Act 2, Macbeth kills King Duncan while he was sleeping in his house. When everyone found out they were devastated and Macbeth claimed title as king.
In Act 3, Macbeth continues killing people that get in his way, including his close friend Banquo who he starts hallucinating the ghost of. People start plotting behind Macbeth's back because he is a terrible king.
In Act 4, Macduff goes to visit Malcolm, Duncan's son, in England. He is requesting his help to get Macbeth out of power and for Malcolm to become king instead. Macduff hears that Macbeth killed his wife and son while he was away and Macduff vows revenge. Meanwhile, Macbeth sees the witches for predictions of the future.
In Act 5, Malcolm's army goes to Scotland to ambush Macbeth. Macbeth prepares himself, not worried because the witch's predictions said that nothing will harm him. He sound finds out that they tricked him when Macduff manages to cut his head off and Malcolm is new king.