What are these spots and patches on the leaves?

[CreamCat]

I got four orchids as a gift about a month ago, they were in bloom and seemed healthy, other than the fact that they had been sitting in water when they got to me. I've never taken care of orchids before so I searched online for information, until a week ago everything seemed to be fine, they lost their blooms and bottom leaf, a couple of them started to sprout a new leaf too. I've just recently noticed some problems.
Orchid 1 has a new growing leaf with dry white spots
Orchid 2 has a couple of black spots on the underside of a leaf
What could they be and what should I do?
I am about to repot them soon since they finished blooming.