Advice

I’m a first time mom, and my son will be 4 weeks on Monday. I understand newborns sleep most of the day, as he does but at night time he has a hard time staying asleep. As soon as I lay him down he wakes right back up and I try to give him his pacifier and soothe him, and he will fall back asleep but won’t stay asleep. Does anyone have any advice on how to get him to stay asleep longer? I do swaddle him, he just won’t stay asleep and wakes up crying.