Please, explain the maining:
2.screw them up (in my language it seems to be vulgar, but in English as if it is not)
It sucks is an all-purpose negative statement meaning you don't like it at all.
To screw [something] up means to make a mess of it, to do it very badly.
"That really sucks, I screwed up another picture by putting my finger in front of the camera lens."