You've pretty much nailed it. 

When you take your written test and pass, you get a piece of paper indicating that you've done so.  This piece of paper is your learner's license.  With it, you can ride a motorcycle but you have to be accompanied by someone who has their full class 6 license.

You require this learner's permit in order to take the Alberta Safety Council course (actually, I'm not too sure about this but I think it's a requirement).  The safety council will teach you over the week or weekend course how to ride the bike and if I'm correct, they bring in official testers at the end of their course and let you borrow their bikes for the road if you feel up for doing that (but you'd definitely need to have successfully done your written test to do this).  Based on how you performed during their training, they'll either recommend that you take the road test or recommend that you don't because you're not ready.

Once you pass your road test, you get your class 6.

Good luck, be safe, and have fun!

You may want to confirm this with a registry but as far as I know, there isn't a waiting period between the time you successfully pass your written test and the time you can do your road test. 

I did the same thing as you.  I took the written test then took the Calgary Safety Council course in Calgary a few weeks later.  Took the road test (actually, it was only a parking lot test then as it was before they changed the requirements) at the end of the weekend course and passed.  I didn't do any riding in between the written test and time of the course because I didn't have access to a bike or someone who had their class 6.

No worries, let me know if you have any other questions!