Is this sentence right?!`my grammar is suck`or` her face is suck`
No, it's "My grammar sucks." or, "Her face sucks." But people don't really say somebody's face sucks.
No. You could either say "My grammar sucks" or "My grammar is bad".
Nope. Not right.
No. The word suck is supposed to be used as a verb, so you would use it in a sentence like any other verb. In those sentences, you are using it like an adjective.