Well you seem to have deleted all the pics I mentioned, which is a shame as other people may well have had more to say about them.
So lets take a look at what’s left. At the start of the second row you have two pics which I assume are of the same little girl. One is taken outside and has natural skin tones ( albeit a bit over saturated) the next shot has been taken in side and is a completely different colour. The whole thing has blue cast. I’m guessing she has a white top (which is blue) and the background is grey? (that’s blue as well) Obviously her skin has picked up the blue as well and it’s making her look like a corpse.
The problem here is that your LIGHTING has the wrong colour temperature. Have you learned anything about that? It looks like you’ve used tungsten lighting and then over corrected it which made it blue. Or you had the white balance on your camera set for tungsten lights but actually took the shot in daylight. It’s easy to fix in EDITING, in fact I’d say it’s day one of any editing course.