Hitler and the Nazis made a few key mistakes in their handling of the Putsch that led to it being easily defeated (Hitler wouldn't have succeeded in installing himself as leader of Germany even if the initial Putsch had succeeded, but more on that later).

The first mistake was made by SA leader Ernst Rohm. He ordered his storm troopers to occupy key buildings, namely the police headquarters and the army headquarters. But Rohm failed to occupy the most important building, which was the army barracks where there was an ample supply of weapons and more importantly soldiers willing to use them.

The other mistake was made by Ludendorff. The Nazis started the Putsch by going into a local beer hall in which the far right leader of Bavaria, named Kahr, was giving a speech. Hitler bullied Kahr into publicly supporting his the Nazis' putsch. Kahr had actually tolerated far right militant groups like the Nazis and his inaction can actually be seen as one of the reasons for the Nazis getting to this point. None the less he would also help put a stop to it. So with Kahr publicly supporting the Nazis, Hitler and his makeshift army went towards the war ministry office. All along the streets they were cheered on by Nazis supporters. Kahr was left with Ludendorff in the beer hall. Ludendorff for some reason decided to let Kahr go. Kahr quickly telephoned the army barracks and the government.

What happened next was a bit of a mess. Hitler and his supporters were met by a group of armed police and soldiers. The Nazis marched at them and began to spit at them and just generally provoke the police. Then someone, its not known which side they belonged to, fired a shot which resulted in the police mowing down several Nazis and causing the rest to retreat.