Replace cam belt

Procedure for setting up timing:

With valve cover off and a ratchet and socket on the crank find TDC for number one cylinder.
Line the crank alignment mark up per manufacturers spec and install is slip the belt on and remember to use woodruf key on each cam and crank. Tighten bolts and crank belt washer. Attach the belt tensioner and adjust. Then turn the motor 10-12 times in direction of operation.

This guide can help

https://www.2carpros.com/diagrams/fiat/x1-9/1983

Install the cam gears with TDC alignment marks pointing at each other, (Position for cam gear marks may vary bt manufacturer).
Turn crank until the intake cam begins to close, once it closes, number 1 is at TDC is right after it. To assure you have it, measure or feel out where the intake and exhaust lobes are positioned. they should be the same angle but facing away from each other. The marking on the crank and cam gear. Spin the engine again by hand and make sure marks for alignment stayed in same place and set at TDC.
Then put in the distributor with the #1 spark plug wire pointing at the #1 spark plug. Then going by firing order install spark plug wires to rotor cap.
Re-Assemble the rest as in removal. You might need to play with lug wires to get the proper length to its plug. Do this one at a time.
Fire it up and check timing with light.

We are sorry we do not have a diagram for you

I parked the car and cleaned the plugs when finished I have tried to start the car by cranking the motor, will not start. Thought it was flooded so I have tried to start the car by cranking the motor, will not start. Then I checked for spark and found none then I contact a mechanic and he said I must replace the module in the distributor which I did. I then tried to start and still no spark after which I found the timing belt snapped. I replaced it and it started but it was not idling well. A friend told me to move the mark on crank pulley to match 12 O'clock, and ever since it will not start. How do I know where are the marks to line up with the marks on the pulleys and in what position must the rotor in distributor be?
I need urgent help as I do not know with what to line up the pulleys.
Thanks, Johnny

Have you done a compression test? This may be an interference engine. Set engine to TDC number one and align rotor to number one plug. This should be close enough to start and run to do dynamic timing.