How is Mussolini's rise to power and totalitarian state in Italy to that of Hitler's rise to power and totalitarian state in Germany?

Both, like most of the world then and now, was developing an economic depression from hordes of excess labor undercutting wages and depleting resources. Overpopulation was not under control anywhere then and the world had overwhelmed the current technology's ability to access sufficient resources for the expanding hordes of people. So it was once again time for the most desperate to attack neighbors and take their land and resources. WW I had slaughtered some excess people but its stagnant trench warfare did almost nothing to acquire more useful land for anyone.

The people of Italy, Spain, and Germany became interested in Marxist international socialist and fascist national socialist policies in their growing desperation. Because thenational socialists promised to protect national industries and its jobs against foreign competition undercutting them, they won the competition between the two radical socialist philosophies.

Italy's Mussolini developed the fascist "corporatist" national socialist structure. It was a more efficient shallow bureaucratic system that "incorporated" each industry under a single government bureau that controlled it.

Spain and Germany copied Italy's model. Italy's economy started improving and it began more conquests south into Africa and east into the Balkans to feed it. Spain became mired with a war against its Marxists who were raging jealous against the national socialist's popularity "stealing" their proletariat from them. Communists from other countries, including the US, entered Spain to help their communists. The German national socialists sided with Franco, Spain's fascist leader, and helped defeat the communists in a fierce civil war made famous by writers like Hemingway.

Germany was the most successful with the system. It was well suited to the traditional German culture's stricter discipline and socialist origins (according to Marx). Their economy improved most rapidly and the world was fascinated at it's initial success until it began its conquest for the land needed by it's expanding population. LIke Greece, Rome, and France before it, it decided to take so much as it could, not just what it needed for the immediate future. The rest is history you should already know.