how can I remove certain fields from the classified ad

how can I remove certain fields from the classified ad placement process? I want to remove the "excerpt" and "cost" fields, for starters. (I already set it to allow free ads)

I also elected to NOT have a featured image required (I uploaded a default image to appear if the person did not upload one themselves). However, whether I upload one or not, it will not publish the ad, saying "this field is required."

I just need some help making this work.