Shotokan, and how it differs from the other styles
Somebody looking for karate in Calgary will find clubs teaching Shotokan, Goju-ryu, Kyokushin, Wado-ryu and more, all called karate and all training differently.
This is what Shotokan is, in plain terms, and where it genuinely differs. It is not an argument that it is the best one. The style matters far less than the instructor.
Shotokan is the most widely practised style of karate in the world. It is known for long, low stances, direct straight-line technique, and a strong emphasis on kata, which are set sequences of movement practised alone. Compared with other styles it trades close-range work and circular movement for reach, structure and power.
The short version
Shotokan works at a longer range than most styles. The stances are lower and longer, the techniques travel in straight lines, and a great deal of training is spent making one movement structurally sound rather than making many movements quickly.
It came from Gichin Funakoshi, who brought karate from Okinawa to mainland Japan in the 1920s, and it is now the most widely taught style in the world.
Where it differs from the others
Goju-ryu works closer, uses more circular movement and more grappling, and breathes differently. Kyokushin spars with full contact and no head punches, which produces a very different kind of toughness. Wado-ryu borrows from Japanese jujutsu and moves off the line rather than meeting force.
None of that makes one of them correct. They answer different questions, and a person who enjoys one will often find another frustrating for reasons that have nothing to do with quality.
What kata is for, since it is the part people ask about
A kata is a set sequence of movements practised alone, against opponents who are not there. It looks like a performance and it is not one. It is how a technique gets repeated enough times to become structure rather than effort.
It is also the record. Karate survived several hundred years without being written down because kata carried it, so learning one is joining a chain.
How to actually choose a club
Watch a class before signing anything. Look at how the instructor speaks to the youngest and the least able people in the room, because that is the club you are joining, not the black belts at the front.
Ask what happens in the first three months, what grading involves, and what it costs in total for a year including the things that are not the monthly fee. A club that answers all three plainly is telling you something about itself.