If you are in Canada as a visitor and wish to extend your stay, you can submit an in-Canada visitor extension of your visitor status in order to obtain a Visitor Record.
The Visitor Record does not allow re-entry to Canada and only provides you with visitor status within Canada.
Once you submit your visitor extension application, you are under implied visitor status in Canada until a decision is made on your extension application.
Here are some additional resources to help you prepare for a visit to Canada.