Napoletana Pizza dough not elastic and breaking
You probably didn't knead the dough for long enough, so the gluten in the dough wasn't fully developed. There are two useful tests to determine if your dough has been kneaded properly.

1.The Poke Test

Form the dough into a ball and, using a floured finger, give it a poke. If the indentation springs back, your dough is nearly ready - knead more lightly until you try test 2. If the indentation remains, keep kneading.

2.The Windowpane Test

If your dough passes the Poke Test, knead it a little more, then pull off a chunk of dough and stretch it with your hands. If the gluten is sufficiently developed, the dough will stretch thin enough to see light through, without breaking. If the dough breaks, knead it some more.

When shaping, even properly developed dough can spring back after shaping if you've just removed it from the bowl. Let the dough relax for a few minutes before trying to shape it again.

Try and avoid adding more flour if you can - wet dough is good dough. Semolina flour is a good alternative to prevent sticking.