What would be a good set of exercises to do every morning to keep me in shape?
Here's a simple morning workout routine that can help you stay in shape:

    Jumping jacks: Start with a warm-up of 10-20 jumping jacks to get your heart rate up and your muscles warm.

    Push-ups: Do 10-15 push-ups to work your chest, triceps, and shoulders.

    Squats: Perform 10-15 squats to target your legs and glutes.

    Plank: Hold a plank position for 30-60 seconds to work your core.

    Stretching: Finish with a few minutes of stretching to loosen up your muscles and prevent injury.

Remember to listen to your body and adjust the number of reps and the duration of each exercise as needed. Start with low intensity and gradually increase the difficulty as you get more comfortable. It's also important to stay hydrated and eat a balanced diet to support your overall health and fitness goals.
I have a sharp pain in my shoulder and therefore cannot perform push-ups. What could be a good alternative workout?
If you're injured, it's better to engage in active recovery and be mindful of any biofeedback you experience. Your muscles won't grow while they're recovering and trying to push through any injury could lead to longer recovery times or longer lasting damage to the area in question. While you wait for your shoulder to recover you could focus on cardio exercises like walking, jogging and swimming. You could also try to work muscle groups that don't engage the injured area. In your case a leg press, squats, crunches, and curls could possibly be good alternatives to pushups.