Do you go to a gym? Are there any trainers there? They’d be the best people to speak to. Ask if they have any kinesiologists. Sometimes gyms provide free training sessions and you can get great advice.
Otherwise you can look on YouTube for exercises. Athlean X is a pretty good reference. But there are a lot of physiotherapy channels as well that have good information.
Is the pain like in the front of the shoulder?
Maybe you need to work your back and rotator cuffs. Also stretch your pecs.
I’d say so, but only on the left.
How can I do that?
Do you go to a gym? Are there any trainers there? They’d be the best people to speak to. Ask if they have any kinesiologists. Sometimes gyms provide free training sessions and you can get great advice.
Otherwise you can look on YouTube for exercises. Athlean X is a pretty good reference. But there are a lot of physiotherapy channels as well that have good information.
Band pull aparts and face pulls are great for shoulder health