Hello, for Class 8, schools prepare their own exam schedules, as CBSE does not conduct board exams. Exams usually cover English, Hindi, Maths, Science, and Social Science, with dates varying by school. The latest NCERT Class 8 books are updated as per NCF 2023, focusing on better conceptual understanding in Mathematics, Science, and Social Science. You can check the detailed schedule and textbooks from this links;
https://school.careers360.com/ncert/ncert-books-for-class-8
https://school.careers360.com/ncert/ncert-syllabus-for-class-8