I only have "regular" flour in the house and I want to bake bread but the recipe calls for bread flour.
you can use regular flour, but the texture will be shorter.
Bread flour has more gluten in it so the texture of the bread will be different than with regular flour.
You can, but it's likely not to rise or hold its risen shape as well as if you used bread flour. AP flour has a protein content of 10-10.5%, where BF's is 12-12.5%. That doesn't sound like much, but in fact it's almost a difference of 20%. I'd suggest really watching the proofing time, both on the first and second proofings, and cutting it short to be safe.