score:3
Hi the page you linked to gives you the clues you need, but is not very clear.
For long distance coach bus travel it's usual to book in advance.
The can-ar coach schedule that includes Moore Falls lists agents where you can purchase tickets.
http://www.can-arcoach.com/wp-content/uploads/2012/04/HaliburtonLine.pdf
You can also make purchase tickets / make reservations via
I can't find any details about if you can pay the driver, however if you can then it is likely that it would be cash only.
You could call them and ask. As you are in Canada it's Toll Free: 1-800-387-7097