The Reserve "job" is broken down by class of service, in loose terms:
Class A = part time
Class B = part time, term
Class C = full time (equivalent to Reg Force)
For your training, you'll be Class B. After that you may be lucky and get an opportunity for more Class B now and then. Class C is only for operations, both domestic and international.
Class A is what most of the Reserves work. This is your weekly parade nights etc. Generally Class A are limited to a maximum of 12 days per month. This is usually only afforded to members in the unit who hold an appointed position (Coxn, Deck O, Supply O etc) who are not already full time. There may be occasions when you get offered days in excess of your normal parade nights. I would recommend that you take them if they fit into your schedule. The more you participate, the more you'll be asked to participate.
As an aside, I saved vacation, statutory holiday time, and overtime hours rather than have the pay, in order to take paid leave from my employer. You may be able to bank hours if your employer agrees, so you can take them later, thereby saving you the trouble of being short for some pay checks.