This makes two loaves.
What you mixed together is called the “leaven”
Add to it:
Prepare counter top by light flour sprinkle and pour dough on counter. Mix and tumble for 5 minutes. Put it back in container and let sit for 3 to 4 hours, cover with towel
Prepare counter again, work for a couple minutes. Separate dough into 2 balls. Work each for a minute and place in proofing basket. Cover each and let set for another 3-4 hours. Or put one in the fridge for next day.
Pre-heat oven to 500F with dutch oven. Remove dutch oven and place dough in it. Take sharpknife and score bread to your liking. Bake 15 minutes, then take lid off and bake for another 10-15 minutes.
Feed starter the night before and place back in fridge, after you make leaven. (50% water + 50% flour)