Advice about my baby

My baby is 6 weeks old and he hates sleeping in his crib he always has to be in arms being rocked once you sit down he knows and wakes up. It’s frustrating that he won’t sleep in his crib he always wakes up what do I do? My friend told me as long as he’s fed changed and everything set him in there and let him cry it out and he’s. Fall asleep is that true? How long is too long to let him cry it out? I’m a first time mom and it’s sad to see him cry like scream cry