The language used in physics NCERT book is very difficult and often students find it difficult to understand from physics textbook therefore many students read from other reference books such as pradeeps and HC Verma therefore if your reading physics for first time will it might be possible that you may not understand all the stuff given in the book therefore you need to seek explanation from the teachers but remember that questions in the exercise are very well and you need to practice them as the level of questions as very good and also the content of book is very good but there are very  omission in the derivations and many lines are excluded there for seek help from teachers