Recovery takes time mate. You can’t rush it as the body needs to repair itself. I recently tore my left front delt and I kept training but lowered intensity on specific exercises. That’s really helped but it’s still not fixed. It’s best just to avoid anything shoulder related to speed up the recovery
Depends on the injury. If it is an impingement or muscle tear? If is the first athleanx has a great video on that. If it is the second you want to keep the shoulder moving less weight like really light weight to help remove scared tissue. Resting can cause muscle tightness to get worse. Stretching will help. Do not do exercises that work that muscle group exactly. You do not want to strain that muscle worse. Work with other muscle groups that involve the muscle group. If it is a broken bone do not workout heavy. Definitely get with a professional. They can help build the right workout plan for you. You will need to find out is the injury acute or chronic. If it happened today. Ice it. If it is older heat. You want to relax the muscles.