Please someone tell me what is the difference and where do you find "cake" flour? thanks

Self rising flour is all purpose flour with baking soda ( I think. Might be baking powder) added. Cake flour, and I'm never even heard of self rising cake flour, would have the same addition. Cake flour has less protein, and therefore will form less gluten than all purpose flour.

I would never , ever use self rising flour for baking cakes or cookies.