I'd use a bleach/water solution with a drop or two of dish soap in a spray bottle. My concern would be the rust on a ceiling. That's very unusual unless you have rods hanging from the ceiling. When you get the mold and mildew off, you will need to figure out how to keep moisture out of your bathroom as that is most likely causing the mildew problem.
I mop mine using a sponge mop and diluted bleach solution. Wear safty glasses and cover your hair!
couple of different websites for you to check out
https://www.doityourself.com/stry/how-to-remove-bathroom-ceiling-mold
https://www.hometalk.com/diy/clean/bathroom/the-best-way-to-remove-mold-mildew-with-2-ingredients-no-bleach-33077514
The Best Way to Remove Mold & Mildew With 2 Ingredients (NO Bleach!)
I'd use a bleach/water solution with a drop or two of dish soap in a spray bottle. My concern would be the rust on a ceiling. That's very unusual unless you have rods hanging from the ceiling. When you get the mold and mildew off, you will need to figure out how to keep moisture out of your bathroom as that is most likely causing the mildew problem.
Wipe over, then when dry paint over with Stain Blocker and then pain when dry!