Only get a canary if you are wanting a canary. Read up on canaries to make sure you wouldn't mind caring for one.
My parakeets enjoy each other's company by preening each other and talking. A canary won't give your parakeet a good companion, in my opinion. Your parakeet may want to bond with the canary, but won't be able to.
I recommend another parakeet, but even then they don't always get along. When having more than one parakeet in a cage, you will need multiple food dishes. They tend to not want to share one food dish and will try to keep the other away, mine did this. I observe how they get along often to make sure things are going fine. I sometimes have to move perches and toys if bullying seems to be happening. You will want a large cage for two and several good toys to entertain themselves. If they are busy playing than they won't pester the other so much.