Use his sigil. An astral temple is not necessary for communication. Focus on the sigil and respectfully mentally speak your words "through" the sigil and to him. He will hear you.
Yes, you should ask him how to grow, but time and effort are needed before one can get such advanced powers. Look at your astrology chart to see what you are good at.
Getting yourself to an advanced state as fast as possible requires firstly doing the basics, and practicing them a lot. Jumping straight into psychokinesis will end up actually delaying you if you are doing it at the expense of meditations that you should be doing.