Put flour in a big glass jar & add enough warm water to be waffle batter consistency and let it sit in a warm room for a few days or so covered with cheese cloth or a clean old rag secured with a rubber band or tie it. You’ll know when it has activated when it starts showing bubbles you can “feed” it with more flour & water. When sourdough doubles in size it’s ready for making waffles. You can join r/sourdoughstarter if you want to learn more from others, but I just make my sourdough starter at waffle batter consistency because it works and it lets me make amazing waffles that taste like sourdough French bread whenever I have “discard” (extra sourdough starter)

IMPORTANT NOTE: After activating, I keep my sourdough in the refrigerator to slow everything down. But, big families keep theirs at room temperature because it goes much faster to feed more people.