For me, troubleshooting is mostly a "divide and conquer" approach.
So, you do things like disconnect the output hose from the washer pump, and make sure it is pumping the fluid. If that isn't working then you check items from the pump back through the supply tank.
If that works then you disconnect the hose feeding the nozzles. If you get fluid there, then the nozzle(s) are clogged.
Basically, you want to prove that the pump is running and pumping fluid, and then concentrate on clogged/broken lines and nozzles.
That's my best shot.....