I realize this is a little late but as someone who has done Prof Oak challenges for most of the main games and am now starting on Insurgence I highly recommend playing through the story normally once or twice and try to make a general guide for yourself as you go through such as what places give the most exp, where all rare candies can be, and especially for this game how and under what conditions (weather and time) to complete all of the events. Combining this information with online resources which truly are your best friend for these kind of challenges will really help you to be confident and thorough once you begin. Make sure you are confident about your game plan because if you happen to miss something because it only had a 1% encounter rate or you just forgot about it and having to restart would really suck.
