you have not told what symptoms you are having

At your age do whatever exercises u want ....don't think much ....just b safe and in weight training do proper technique

Being an orthopedic sports injury surgeon,i can recommend to learn technique instead doing yourself without knowing proper technique. There are multiple excercise where your joints are highly susceptible to injuries like not knowing proper technique of deadlift,not using belt etc. Even squatting and overhead benchpress excercise can be dangerous if done with wrong technique.. I have seen pt with isolated upper pec injury,who came to me with complaint of chest pain while doing Inclined bench press...another important to do is proper warm up.. One of our patient,who is elite athelete came to OPD with Pectoralis complete tear..so know techniques first,do proper warm up,and do under supervision.

Do yoga based exercises. You can learn them from my video 'me and my yoga 'in my YouTube channel 'dr nc gupta' These exercises are more effective than gym exercises.

Distribute the exercises and workout as a parts and start a workout. Build your muscles as much as you are fit and not too bulky.

For what you are asking?

Core body strengthening exercises you can do