Does Canonical collect any user data about me or my habits during my use of Ubuntu? And if so, how can I stop this data collection?
Yes and no. If you're browsing the internet, you can be tracked on anything since you're requesting data from external servers, which keep track of that data and when and who from it was requested.
If you're talking about spyware, there are very few spywares out there for Ubuntu, but they're out there. Linux is "Security through Obscurity"