I'm a little puzzled as to how you got access to three Spheres, but I'll do my best to answer the question presented.
You need to take the Traits in the associated Sphere to learn Powers from that Sphere. Which Trait you take determines what Tier of Powers you can learn, although I believe some Spheres in the Path of Darkness allow you to take a Decrease Characteristic 1 to learn a single 1st Tier Power for free.
As for the Psychic Awareness ability itself, Insekts with it cast using Discipline instead of Willpower, and have Traits in each Knowledge Branch to make casting easier. The X appended to Psychic Awareness appears to determine how many Traits you may select from your chosen Sphere of Influence.
I'm a little puzzled as to how you got access to three Spheres, but I'll do my best to answer the question presented.
You need to take the Traits in the associated Sphere to learn Powers from that Sphere. Which Trait you take determines what Tier of Powers you can learn, although I believe some Spheres in the Path of Darkness allow you to take a Decrease Characteristic 1 to learn a single 1st Tier Power for free.
As for the Psychic Awareness ability itself, Insekts with it cast using Discipline instead of Willpower, and have Traits in each Knowledge Branch to make casting easier. The X appended to Psychic Awareness appears to determine how many Traits you may select from your chosen Sphere of Influence.