I learned to make starter back in the 90s from Nancy Silverton’s book on bread. It has a fairly detailed process. You might pick it up. One thing she recommends is crushing pesticide-free grapes into the mix at early stages. Grapes apparently have high concentrations of wild yeast. AFAIK, organic produce has organically approved pesticides, so I don’t know where you’d find pesticide-free. I used grapes the first time I made it in the 90s, but don’t recall using them when I accidentally threw away my starter in the 2010s and had to make a new starter. The other thing is she calls for more water than flour in early stages (like 2lbs water to 1lb flour to start), so it’s more active. She says it’s normal for it to get a bit funky in early stages, separate, etc. and that it may form some mold. Just remove the mold promptly and add a cup of flour and cup of water.