For starters, Hitler started to target the Jewish population by restricting their rights and freedoms. He prohibited them from going to some institutions, staying out past a certain time, marrying with other races, etc. He also encouraged people to burn down their businesses and homes. I would ask you to look up the event of "Kristallnacht". (It will help give you some perspective as to the atrocities committed against Jews.) Also, during the war, Hitler forced Jews to live in Ghettos and transported them to concentration camps and death camps.
