I never quite know what this means. Pictures would probably be helpful. Your profile pic looks just fine. Very few people have perfect posture, and even those with very strong, muscular upper backs/shoulders tend to have rolled-forward shoulders, and if they spend a lot of time on phones/computers a slightly hunched neck. It’s kinda hard to not have in today’s world.
It’s not also necessarily bad, you know? If you’re getting bigger and stronger, and stay injury free, then whether or not your shoulders aren’t pulled back 24/7 probably doesn’t really matter.
I have some shoulder issues myself, and was directed to this thread:
Read through it and see what you think. I’m slowly addressing different parts of it. Take this with a grain of salt since I’m no expert, but if you want to just get bigger and stronger, and are young and healthy, just do 5/3/1 (or any program designed to get you stronger), slowly getting stronger at the big lifts, and also do things like rows, pull aparts, etc. as assistance work. My plan right now is to find ways to work my upper body while also addressing my shoulder, I just need to find ways that don’t hurt me. That doesn’t sound like it’s really an issue for you though. If you start while you’re young, doing some back work along with your pressing should keep you healthy for at least a while (hopefully!).