I know it had a different name when it was introduced, because the old RESO consisted of RESO I, a four-week basic leadership training course in May in Gagetown, followed by the Basic Infantry Officer Phase II (with Regs and Reservists together). All arms did the Common Phase of Phase II (ten weeks) before heading to their respective schools for four or five weeks for basic classification. This qualifies you to 2Lt in the Reserves. Then the following summer you would do Phase III in your specific MOC and generally this is the end of your training and qualification to Lt. Then next courses you‘d go on would be higher level courses later in your career.
To this day I rue the fact that an injury in week ten cost me the last Phase II course run and I couldn‘t get onto the Reg Force Infantry Phase III as a result. That‘s beside the point, though.
The program now is more modularized like a program we used to have called MITCP - it can all be done in two week blocks, or if you are student, in one summer. You start by doing BMQ through your unit - Basic Military Qualification (which used to be called QL2) with the non-commissioned recruits. After this course you take a course called Basic Military Officer Qualification, which is a non-field one week course in staff functions, battle procedure, and estimating. Then after that you do the Common Army Phase, which is essentially a section commander course condensed, where you learn fieldcraft, the C9, section attacks, navigation, and patrolling. This course is five busy weeks as it covers all the material that was covered in Phase II Common in less time, basically.
After CAP(R) you progress to courses specific to your MOC. Where these are conducted depend on your MOC. Combat arms courses are at CTC Gagetown, I can‘t speak for others except for Signals which is at CFSCE in Kingston. Most of the other CSS-type trades are taught at CFB Borden, I imagine, since that‘s where CFSAL and CFSEME and so on are.
At the end of all this training, you are qualified to hold the rank of Lieutenant, though you won‘t generally get it right away.