In order to pass CAS, you need to:
1) Complete the 8 learning outcomes:
- Increased their awareness of their strengths and areas for growth.
- Undertaken new challenges.
- Planned and initiated activities.
- Worked collaboratively with others.
- Shown perseverance and commitment in their activities.
- Engaged with issues of global importance.
- Considered the ethical implications of their actions.
- Developed new skills
At the end of your course, your CAS coordinator will ask you to fill out an IB form, where you will have to identify all of these learning outcomes in your reflections, so try to focus your reflections on these things. Not just describe what you do, write about how the activity you did helped others and/or helped you, what did you learn during the activity?, was it difficult?, was it easy?, why?. CAS reflections are supposed to help you know yourself and the world around you, and the real change that one person can do. =)
2) Have a minimum of 150 CAS hours, which as you said are divided into creativity hours, action hours and service hours. But always try to do activities which involve more than one, that's why is called creativity, action AND service, and not creativity, action OR service.
And that's it!

Oh, a clarification, the learning outcome #3 (Planned and initiated activities) is basically a personal project, it's an activity in which you will have, for example, to contact the person/institution where you will be doing your project, plan what you are going to do, coordinate the days and hours, etc.
I don't think I'm missing anything, but if I'm, probably someone will post it below