Whisk together the yeast and water, until the yeast is dissolved.
Mix together the flour and salt in a bowl until fully combined.
Add the sugar, then pour the yeast/water mixture into the bowl. Slowly mix until the water soaks into the flour.
Add the oil (if using) or more water if needed and knead until the dough looks shaggy but not too wet or sticky.
Very lightly drizzle the bowl with olive oil being sure to brush up the sides of the bowl also to prevent sticking. Cover with a towel and keep somewhere warm so the dough doubles in size. (depending on the temperature of the room this could take 1 to 3 hours or more)
Lightly dust your workspace with flour, gently shape the dough into a loaf or your desired shape. Then set aside on parchment paper or a baking sheet to proof again until it doubles in size. (could take 1 to 2 hours or more). Then score the top with a sharp knife to create vents, just a few will do.
Preheat the oven to 425°F. (Optional: Preheat a pizza stone) Bake for 25 minutes. Remove to a cooling rack until fully cooled before slicing.