The bread dough that I am making calls for it to rise for 1 hour, knead for 5 minutes, then rise for another hour, shape into loaves, rise for 45 minutes, then bake. So can I freeze the dough after the first rise?
Yes, you absolutely can - this is the common way to freeze dough, actually. It's better to freeze after the first rise. Often the second rise will be done in the refrigerator along with thawing; and most of the recipes I've seen skip a third rise (so you freeze the dough shaped, and you're rising in shaped form alongside thawing plus a warming stage while you preheat the oven).
I here make the dough. Let it rise. Kneed it down. Put it in a bread pan 1/2 full. Let it rise to full. Cover & freeze. Remove when needed. Remove cover. Let thaw. It will start to rise again. Bake it rises a little more. Do the same with pizza crust.