Just bought a 1996 ford Ranger whit a 2.3 My concern is. Timing belt broke I have already cranked it 15 times would that damage engine?

Because the oil pump won't be turning so no oil.

My dad has a 2000 ford ranger, and he starts the motor without oil in it when hes changing it. He calls it "flushing the block"

You bought a vehicle without a service history.
Camber changes on schedule are essential without it the car is worth a lot lot less.
Getting on oil pump to run dry is extreemly stupid as it will not always pick up again.
I know oil pumps that have to be primed before start up after work on the engine.
If it is an interference engine it is now a paperweight.

An interference engine is one that has insufficient clearance between the valves and pistons if the cam stops turning due to a broken timing belt. The result is usually catastrophic engine failure. Not so with a non-interference engine. That vehicle has a non interference engine which is a good thing BUT you need to have a qualified mechanic inspect it for a diagnosis

How is the oil pump not working? Your concern should be whether the motor is an interference motor or not. Does it sound like you still have compression? If not all the valves are bent.

If timing belt broke your timing won't work, engine will not work, car will not run