Wenn jemand z.B. Madrid besuchen will, kann man dann sagen?
Für zwei Woche gehe ich nach Madrid.
You need to decline "Woche": it must be plural when you talk about two weeks.
It's also more idiomatic to put the subject into first position:
With "gehen" it's still a bit colloquial; you'd usually drive:
Note that "für zwei Wochen" means you'll be staying there for two weeks, and it provides no information about when you plan to go.
If what you're trying to say is "I'll go to Madrid in two weeks", you'd use "in" in German: