Welcome from Ottawa
. Never be afraid to ask questions here
As for working line (or WL as the abbreviation) vs. showline (SL), it's a personal decision. Some people shy away from WL because they can be high drive dogs and high energy, while some shy away from SL due to the physical structure and sometimes temperament issues. There is no sure thing in either, you can get a hyper SL or a lazy WL for example. Same thing as male vs female
Both types can be family pets and protectors, the best advice especially if you're interested in doing Schutzhund is to find a local club and see their dogs in action so you can get a feel for what's required. The club can also point you towards breeders that have proven progeny that work well. Talk to breeders and express what you're looking for and they should be able to tell you whether they have a good fit for your family. Pay attention to their contracts and what they cover for health and temperament
If you'd like recommendations for breeders we can help out as well. In Ontario there are two WL breeders I personally would recommend:
I got my GSD from Stalworth Kennels outside of Ottawa. I'm extremely happy with Delgado who is just shy of 11 months, solid temperament, nerves of steel, great around kids and other animals (other dogs, cats, chickens, sheep, horses, and cows). He loves to work, I'm planning on doing agility once he turns 2 so just sticking with tracking and obedience right now.
Carmen at Carmspack also has a great reputation and is also a member of this forum. Her dogs excel in their working abilities and she's a wealth of knowledge in both health and bloodlines. She's located near Toronto