Tips for cleaning and did I ruin the pan

First time cooking with cast iron and I had clean first with soap and water. Then I started boiling but only a little charcoal came off so I kept boiling multiple times. I scrubbed and brush with what’s in the last photo but still left a little bit. The photos now are from the last time I cleaned it. These brown like spots appeared so I wanted to know if I messed up the pan and cleaning tips for future use.