For the dry skin try a good cleanser instead of using a face wash. Then you can apply a moisturiser and sunscreen. Black spots are because of the post inflammatory hyper pigmentation and for that spot peeling can be done. But takes longer time to resolve. Acne is because of harmonal changes at your age and need maintenance
Next Steps
Kindly visit any qualified dermatologist and get expert treatment
Health Tips
Avoid using harsh soap
Don't pick acne
Avoid direct sunlight