when will my page rank be calculated and recognised by google toolbar,
Anybody's guess on that one - could be a month, could be two.. or could be tomorrow.
or has it already and it is just zero?
Possible. PR is calculated based on the PR contributed by those pages that link to you. Do you have incoming links from other sites? The number of links and the PR of those links will give you a rough idea.
If zero, does this mean I've been penalised?
Not necessarily. Could be your PR hasn't been calculated. Could be your PR is less than '1'.
Too much of a novice to have deliberately done something wrong