What is important for a good review?
A review is nothing more than an objective, reasoned assessment or criticism of a particular work according to very specific criteria.
Here you can use the following structure not only for book reviews, but for all other types of reviews - you then have to adapt this only to the respective medium.
It is important that you do not write your own rating but substantiated statements including thesis and arguments for justification. You also have to fill in all the points that you write in the context of this with the appropriate quotations and / or lines. As an aid to this, you can imagine being a well-known book or film critic, who now criticizes the corresponding work for given points and substantiates this criticism with arguments.
Even when a novel is written so factually and sober: Even if the plot is exciting, you must build in the review no emotions or tensions.