//So after the “Big Bang “. Matter and gas was flung out in all directions. //
It wasn't, though. Space expanded, and the matter followed it, but there wasn't a "great flinging out" of matter and gas.
As to the actual question, I don't think the rotations need to be "set up". They would emerge naturally from, say, some matter coalescing, and other matter nearby travelling merrily on its way but getting caught in the gravity well and following the inevitably curved path (that or joining the "central" mass).
I don't think the rotation needs to be "set up", then. It really would just be a consequence of the basic laws of physics.
(PS: danny, ye of little faith...)