Its v. simple bro... Just go to on this link
https://www.canada.ca/en/immigration-refugees-citizenship/services/application.html
Create an account it will ask you for GCkey just signup as a GCkey and fill the form. The system will ask you some Secret questions and keep your answers that questions. but remember write down that answers because at the time of signin the system will ask you answers.
after created your account there is option in side the account that Linkin your paper application online. just click on that and they will ask you about your application for example your travelling dates your application umber and your passport number and expiry dates. Thats it your account will b linkin and all updates will be shown there.