Congrats and good luck!
Don't forget that you can scout players, but removing them from the squad afterwards will lower the team enthusiasm, so you'll have to lean on owners answering bb-mails for this season I'm afraid.
There is a tool (nt-scout) that will give you the list of all canadian players 20-21yo, you can then filter by salary, it will give you a very rough idea of what you have available. Salary is not everything, but it's rare 7k players have what it takes to make it and have an impact on the team.
Once again, good luck, it seems there's a core of managers on this thread that can help you at least for the rest of this season