How to lighten (or make less dense) pizza dough
You really need the dough to double in size for it to not be overly tough.

30 min might be enough time under some conditions, but it's not always; if you're in a rush, you might be better off making a biscuit dough rather than a yeast dough.

To ensure a good rise, I'd recommend the following:


Make sure to use warm water.  I run the hot tap 'til it feels a little warmer than body temperature.  (I check it against the inside of my wrist).
If using a metal bowl, pre-warm it by filling it with hot water, then dumping it out.
Proof the yeast to make sure it's active -- Add the yeast to the warm water (possibly with a little flour or sugar) and wait 'til it foams up before adding the rest of the flour and other ingredients (especially the salt)
Allow to rise in a warm, but not too warm place.  Sometimes, a low oven is too warm and will kill the yeast.  In the summer, I leave it in a sunny place, in the winter, I put it on top of my radiator.  If you don't have radiators, but you have an electric heating pad with a low setting, you might try that.  Rather than turning on the oven, you can also put it in there, but rather than heat the oven, boil some water separately, and put it in the oven and pour it into a shallow tray to add some thermal energy.


If the dough has doubled, and it's still coming out too tough for your liking, you can try:


Add some oil (olive oil or neutral flavored oil) to the dough.  Try a tablespoon or two.  Add it before adding in the water, and just mix in what water you need for it to form a dough.
Switch to an all-purpose rather than a bread or strong flour, or a blend.  (or a blend of whole wheat and bread/strong flour)