How do I structure an essay properly?

It's actually really easy to do your essay structuring right. I always followed this formula and still do! I use PEE. This is simply Point, Evidence, Example. So, if the question is, 'how did Hitler gain power in Germany after WW1' you would start your paragraph by saying

1. POINT: One of the reasons Hitler gained power in Germany was because of his war hero status that resulted from him fighting during WW1.

2. EVIDENCE: He was awarded the Iron Cross.

3. EXAMPLE: This meant that Hitler was well regarded by the German people as they looked up to him for his efforts in the war and favoured him over the higher level officers who were blamed for Germany's loss. 

This is a very simplistic version and you would need to elaborate a bit more, but you can get the gist!