Of course, it is not good to go to training without class. No matter what you do, you should focus on learning, and everything else is auxiliary. You can't delay classes for training. Classes and training are certainly important among them, so you must go to classes. If you don't miss class, it's ok to go to training. Try to attend classes when you have classes, and the training can be postponed or not.

It is not good for children in the senior high school entrance examination to concentrate on tutoring, because tutoring institutions are never as good as school teachers. Therefore, try not to leave school to make up lessons in outside institutions, which will affect the children's own learning progress.