As a PRes Infantryman(I assume you are still in BC?), you're probably better off taking a French course on your own dime, than waiting for your unit to send you on a French course - Not sure how many Reserve units would be willing to pay to send a member on that course, or what if any positions would be available to PRes units. The online course, if still available would probably be the most realistic(at least as a jr rank).
At the beginning of your Reserve career, your unit is going to be more focused on getting you through BMQ and DP1. After that, it'll be DP2A(Weapons Det Member), driver courses, PLQ, etc.
As for what second language training is available through the CAF, there is the year long French course as well as classes(not sure how long, or often they run) at some bases, plus the online course(if still available).
*edited to add, here is a thread about SLT from a few years ago
http://forums.army.ca/forums/threads/97672.0
Info about the online course - the allies.forces.gc.ca link no longer works though
http://forums.army.ca/forums/threads/99459.0