Patience is key to any warrior's training. Fight in network battles 30 times using the standby function. The longer you wait, the greater the joy will be when you finally get picked.
Your objective should be to raise a single character to level 30. There is great meaning in accomplishing what is difficult. To find your answer, you must set your sights high.
So you wish to learn Yoga? If that is truly the case, then first you must complete the Character Story with all characters. There is great merit in walking each of their individual paths.