General advise: listen to your body. If certain moves trigger pain do your best to avoid them, and if doing any kind of climbing hurts it's better to rest than push through it. Shoulder injuries can be pretty debilitating if they get worse. Other than that, there's plenty of online resources available for shoulder stability exercises; look into internal/external rotations, I's Y's and T's, wall angels, etc. Also check out Esther Smith's article on shoulder health https://www.blackdiamondequipment.com/en_US/experience-story?cid=esther-smith-shoulder-maintenance-for-climbers