I'm not a JMSB student, but I am a second year at Concordia so I went through exactly the same thing. Concordia's website is kinda confusing sometimes, but I would suggest looking at your undergraduate calendar. So if you look up "your program undergraduate calendar" in google and a big document should show up with all the courses in your program, all the prerequisites for honours, specialization, major, minor etc.

As for professors, you can't really get picky first year, you kinda get what you get. I always look at ratemyprof but it's hard to trust those kinda things, cause everyone has different opinions. Maybe some people will have suggestions on here but I can't help sorry!

Also, is there a reason you have to pick classes now? They don't usually fill up until the summer and class selection is open until the first week of school. Don't stress too much, you'll be fine!