My world issues teacher in high school told us that allied generals wanted to continue fighting in order to bring a total victory against Germany, is this true?
He also told us that they believed they would come back in ~20 years to "finish the job"
I haven't heard anything to that effect and I'd be very surprised if it's true.
1918 was by far the most violent and costly year of the war, with fighting going on at high intensity from the launch of the German offensive in March straight through to the armistice in November. The idea that another major offensive in 1919 wouldn't be needed can only have been an immense relief.
What's more, it resembled a surrender more than a truce -- Germany gave up its naval and air forces in their entirety, many of its army units disintegrated before they'd even completed the march home, allied forces occupied the Rhineland unopposed, hunger was widespread, and a brutal civil war erupted between anarchists and right-wingers in its cities that left its new Social Democratic government a helpless spectator.
Germany was in no position to resist any Allied demands. The only reason it wasn't occupied completely was because the Allies weren't interested in doing so.
The General your teacher was probably referring to was Marshall Ferdinand Foch, Generalissimo (Supreme Commander) of the Allied Armies. He believed that Germany had not been sufficiently restrained by the Versailles Treaty (he was right), and thought that it was 'an armistice for 20 years'. I'm less deterministic about the Treaty, but history proved him to be correct.