Since your primary objective is a certificate and your objectives of knowledge acquisition and skill mastery are secondary, then the certificate dictates what you need to study. Research the PMI website and obtain and read the PMBoK. The PMBoK will steer you to the knowledge and process areas you need to learn and then you can find those courses, sign up, and take them. There are many PMI-approved vendors out there that provide this education; however, many of them teach to the test. Since your time frame is a year out, I suggest you find courses that teach the content instead of how to pass the test. Because that will help you meet your secondary goals.
If knowledge and skill mastery were your objectives, then your two questions you need to answer are: 1) in what are you interested that you may wish to seek a specialty and 2) in what areas are you demonstrably weak?
These answers will dictate your next set of courses.
Since you're just beginning, I'd suggest to reverse your objectives.