I have to chime in and agree about baking with a scale. The simplest sourdough recipe, is one I go back to repeatedly. More detail can be found online by searching for 1-2-3 sourdough.
Basically, its’ (by weight) 1 part sourdough starter (100% hydration, or equal parts by weight water & flour), 2 parts water, 3 parts flour. Then add the weight of the flour, half of the starter, and multiply by .02 (2%) to get the amount of salt to add (again, by weight). For my standard 2 loaf recipe, its 200g starter, 400g water, 600g flour, 14g salt.
Mix everything but the salt and let it sit for a couple of hours. Do not knead yet.
Spread out as thin as possible n a floured countertop, add about half of the salt. Fold in half, and add more of the salt to the top, fold again and add the rest. Knead for a couple of minutes, put in a bowl to rise, and walk away. Every 20 minutes for the next hour or two, come back, stretch the dough out on a floured countertop, then fold in thirds and roll up. Put back in the bowl.
Let it rise until near doubled. Shape and put into a banneton (well floured basket) to rise, or into loaf pans. Refrigerate until you’re ready to bake.
Preheat oven to 425 or 450 (depending on how dark you like your crust). Put a metal baking dish in the bottom of the oven (I leave mine there 24/7/365 filled with lava rocks) Boil a teakettle full of water. Once up to temperature, remove your risen loaves from the refrigerator and (if in bannetons turn out onto a baking sheet or stone) slash the tops with a sharp knife, then put directly in the oven. Pour the boiling water in the baking dish on the bottom of the oven. Close the door and wait 15 minutes.
Rotate loaves at 15 minutes to ensure even cooking.
Cook until the internal temperature is 200F.
The slash on the top ensures the loaf can continue to spread as the loaf springs up in the oven and the crust begins to form. The water flashes to steam and keeps the crust moist enough to allow the oven spring (yeast giving up a last gasp of effort/CO2 as they are exposed to heat and head off to their maker) to allow full expansion of the interior.
Cool for at least an hour before cutting and spreading on the best butter you can find.
Hide the fresh loaf from your family and friends so as to hoard like Gollum’s precious.