I believe Freedom of the city is more of a ceremonial term. St. Julien's is a big part of the Calgary Highlanders tradition and it is taken very seriously. That is why, rain or shine, snow or 100km/h wind, on one Saturday in April, streets will be shut down and soldiers will march through downtown Calgary.
And I can tell you it is a pretty cool experience.
I don't think freedom of the city has anything to do with the regular exercises that the different regiments do in the city. The city, the Police and the Army Regiments here have an understanding and work together in this regard. Canadian troops have free mobility to move around the city, they are not restricted to a building.
If you are at a downtown bar on rememberance day, St. Juliens or a few other Military holidays, there is a decent chance you might run into a soldier in full dress uniform.
The Calgary Highlanders meet every Wednesday night at 7:00pm at Mewata. If you want to see what happens, you can go down there and try to catch a glimpse. They do a lot of different things. Sometimes, you may not see them at all as they are doing classroom work or other things like that, but a lot of times they will be doing parade practice, cleaning weapons, doing PT etc.
If you are interested in joining, it might be a good idea to go down and see what is going on to see if it is right for you. There are a lot of good people there.
If you run into soldiers doing an exercise in the city and they look buys to you, don't bother talking to them. They are trying to work. They're just like you in that they don't like to be bothered when their trying to get something done. But if the soldiers don't seem to be do an exercise, by all means approach them and start talking. Most will be more than happy to talk to you and explain what they are doing.
It's kind of difficult to alert the public to exercises going on. It's not like the Army has thousands of dollars set aside to run newspaper ads or anything. They could probably do it through Twitter or Facebook, but again, the military has never been quite up to the new tech and these people have day jobs as well. Generally the exercises being run in Calgary are on the extremely small scale. They are done during weeknights, and are done just to keep the soldiers in that state of mind. These are reservists soldiers were are talking about. They train once per week at Mewata, and it's not like they have a huge area to do this training. You can't stay couped up in Mewata every time. Once per month weekend training is done and that is generally on base in Wainwright or Edmonton or other crown land around Alberta. This is where they would be using blanks and/or live ammunition.
And just a general FYI, in military terms, this is a gun (Howitzer 777):
This is a rifle (C7):
This is a Light Machine Gun (C9):
This is a General Purpose Machine Gun (C6):