Can a newbie control rust? or Honey I Think I Finally Found THE Car!

USE IN WELL VENTILATED AREA. It has Isocyanates in it. I wear a charcoal filter mask myself. Especially if i'm spraying or brushing it in a fender well or trunk space.
Yeah, I'll either wear an organic filter or borrow a buddie's fresh air hood. I'm still reading about this stuff, but I'm wondering how you rinse the two prep steps inside a trunk or floor pan with only surface rust / no drain holes.