Associate or first level exams are meant to verify good base knowledge of a particular MuleSoft product area. The keys to passing these exams are: 1) Possess the appropriate (preexisting) technical skills; 2) Attend the recommended corresponding training course(s); and 3) Study and grasp the course material thoroughly.
The topics covered in an Associate exam are exactly what is detailed in the course description of the corresponding course(s). Consult the list of training courses.
Download the MCD - Integration and API Associate preparation guide.