Sleep training

FTM here. My baby is four months old and I’ve been trying to get him to put himself to sleep. What are some tips on making it the least stressful for my baby? He will stare at me and scream until I pick him up when I try sitting next to him. He will not cry himself to sleep, I also can’t handle that. I’ve tried different sleep sacks, white noise, different environments such as living room, bedroom, baby room, etc. I feel like I’m doing something wrong when I see younger babies put themselves to sleep but he still seems to need me. Any advice helps - thank you.