Why is he crying?

Hello, I am a first time mom and my 8 week old son cries and fusses every night from around 9pm-2:30am, he isn’t hungry (I try feeding him), I make sure I burp him, he won’t fall asleep either he just cries and fusses until he wears himself out and falls asleep, he started doing this when he was 7 weeks old so for the past week, anyone know why or what I can do to calm him?