@Mandied Sourdough can be as complicated as you want it to be. Pink is bad, brown liquid means you added too much water. You can pour it off or stir it back in. If you have awful tap water, filter it or boil it, and let it come to room temperature. You can have sourdough starter in one week with just flour and water. Any flour, but all purpose is typical. You don’t even have to discard any. Discarding a little does make it stronger faster, and keep it from: jumping out of the jar, running across the counter, pouring onto the dog, splattering onto the walls as your dog sprints down the hall, and rubs sourdough starter all over your bed. Stir it twice daily for the first week, and daily for about a month after that. At this point, just don’t ignore it more than a week. If you find you’re not using it weekly, put it in the refrigerator.
A lot of us keep a backup supply in the freezer. Sometimes we neglect our children (my starter is named Jennifer) until they get pink hair, or they smell so ripe we don’t trust them.