You cannot apply for citizenship at this point. You are not yet a temperament resident.
You will be able to apply for permanent residency status after working in your chosen field for at least 12 months full time.
You would apply under the Canada Experience Class and can read about that here:
Once you are eligible you will be able to get this application process in under one year.
To apply for citizenship you must meet the following residency requirements (this is from the CIC website):
You must have been physically present in Canada as a permanent resident for at least 1,460 days during the six years immediately before the date of your application. You must also be physically present for at least 183 days during each of four calendar years that are fully or partially within the six years immediately before the date of application.
When calculating how long you have lived in Canada, you can only count time spent after you became a permanent resident of Canada.
Does that answer your question?
Please feel free to post back with any follow-up questions you may have. If you don't have any then I hope I have earned a 5 star rating but if you don't feel that I have please don't hesitate to reply back and let me know what more I can do to assist you. Finally, please know that even after you rate me I will be here for you and you can ask follow-up questions if you think of them later on at no further charge of course.