I am assuming you are referring to chapters in our lecture notes.
All of the chapters are important, and there will always be some questions in the exam on these chapters (most likely in Section A of the exam).
It is impossible to guess how many marks – it varies from exam to exam and the ACCA does not give weightings to different topics.
(There isn’t really an awful lot to learn in the first two chapters – it shouldn’t take long to watch the lectures on them. However they are fundamental to an understanding of the role of the financial manager.)