Basically anyone can make a psi ball. If you can't then you are dead. Everything in life has energy therefor You can will that energy to one area to produce physical phenomena to occur same with telekinesis.
Basically you are focusing your energy between the middle of your hands. If you are new then rub your hands to create friction and produce energy
Well psi energy is just the bodys natural energy. For me psi energy or chi as I call it warms my body when I use it. By a few degrees too. Plus it helps being in harmony with your body. I have noticed since I began using my chi that my body burns energy faster. Plus I have more energy for the day.