Is it possible to have an input, say a button, that does one positive edge clock pulse? So I want to press this button once and it does a 0->1->0. I can't think of anyway to do it because it changes twice with one input.
A single clean pulse can be created using a latch circuit, (cross coupled gates). Ideally this works best with a switch or push button having a SPDT format.
Another option is to use a SPST switch with (debounce) filtering which is basically an RC filter followed by a Schmitt trigger circuit.
One more idea is a one shot circuit using a chip such as a 555 series timer. With a 555 design you can even set up the desired pulse width.
Here is a Google link showing several of the above mentioned designs: