I didn't write it, because I didn't want to risk being marked wrong, but could this possibly be translated with "This town has nothing to offer me"? I know "offer" is usually "erbjuda", but doesn't the meaning of the phrase fit better with this?
It must be in the definite.
After denna, either works, but the indefinite is formal and the definite is very informal. But after den här, only the definite is used.
There's a short version of the word staden, stan, which is definite too.