Good day,
The basic eligibility requirements that are to be met prior to submitting an application to Join the Primary Reserves or the Regular Force of the Canadian Armed Forces can be found on our recruiting website under the Apply Now section. I have provided a link below that you can copy and paste into your browser. Once you meet the basic eligibility requirements you may submit an online application through the forces.ca website. In reference to specific courses, each occupation has it's own educational requirements and not having a grade 10 math or a completed high school diploma limits the occupations that you meet the educational prerequisites for.
http://www.forces.ca/en/page/applynow-100#join
Furthermore I recommend that you talk to a Primary Reserve recruiter at the Primary Reserve unit in your area. You can apply to the Primary Reserve Force while you are in grade 10 full-time (or secondaire IV for Quebec residents), provided that you are 16 years old and a Canadian citizen. You may require a letter from your school, indicating that you are going to meet the academic requirements for grade 10 (sec IV).