Have a minute? - won't this be correct?
We must use the auxiliar verb do together with the personal pronoun you when translating it to english.
What you said would kinda be the literal translation
While that is technically correct, in this case people ask "Have a minute?" all the time. This is a very casual way of speaking but as a native English speaker I may say it like this. However it is probably not best to teach it that way.
Masz minutę ? Masz dwie minuty ?
Does this phrase have the same meaning in Polish as the English phrase?
I guess so, it means "Do you have a moment?", more or less.
wot case is this if i may ask? Accus?
Accusative, as needed by "mieć" = "to have".