Each Paraliminal has a "tagline" that will help you to ascertain what will work best. Automatic Pilot is intended to "Eliminate negative self-talk and vaporize self-sabotage." Get Around to It helps to "Eliminate procrastination and succeed by design."
See which description seems most pertinent to your specific situation and proceed accordingly. The two would also work great together.
If you do experience a lot of second guessing yourself or doubting your capacities, you might also want to consider incorporating the Belief Paraliminal into your listening schedule.
With regard to frequency, everybody's different, so pay attention to what works best for you. The same holds true for how soon you will see results. That's one of the reasons Paraliminals work so well, they're so organic and you can adapt them easily to generate your own personal best experience.