meanings of 2 expressions

[learner2007]

Please, explain the maining:

1.It sucks
2.screw them up (in my language it seems to be vulgar, but in English as if it is not)

[mykwyner]

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."