Dear student,
The similarity between the nutrition in amoeba and in human beings is that both the organisms are heterotrophs and they obtain their nutrition from other organisms. Thus, both of them show the heterotrophic mode of nutrition.
The difference between the nutrition in amoeba and in human beings is that the human beings have a complex system of digestion called as a digestive system which involves different organs and the different nutrients are digested in different parts with different chemicals. In amoeba, there is no such any kind of digestive system and all the food and the nutrients are digested in the single structure called as the food vacuole.
Regards