I'm starting to learn that you should work out more than a few days in a row. My chest and shoulders never seem to get a rest (except on leg day) and I've come to believe it's stunting my growth.
I would doubt that you would need 12 sets for either biceps or triceps,and after training for only 3 months total,I would advise doing 9 sets for bigger bodyparts and 6 for smaller ones.
What are you going to do when you become an advanced trainer.............20 sets per bodypart?
Start offf with less volume,but train harder.
3 exercises,3 sets each for chest,legs,back,and 2 exercises 3 sets each for shoulders and arms.
You are most likel;y doing too much at your stage of development!