Hello! For sentence number 1 I would use "turn out" and I would use "good" For sentence number 2 I would say "the trash from the bathrooms" And you can say "clean the whole downstairs floor"

1) Do you say "My cake didn't turn out/come out so good or well"? And "I tried to make a cake, but it didn't turn out very well/good"? I would say "My cake didn't turn out so good." and for the second question you could use both, whatever feels best. 2) If your house has two bathrooms in it, would you say "I have to take out the bathrooms' trash" or "I have to take out the bathrooms trash"? OR "trashes"? Hmm this is kind of a tough one. I would say that "I have to take out the bathrooms' trash." sounds best. 3) Can you say "Clean the whole downstairs floor"? Yes you can, but I think "Clean the downstairs floor." sounds a bit better. Hope this helped! :)