Don't know what exactly your case is.
If you already got a letter of acceptance, it should be indicated how many courses or credits you are suppose to take.And all the other things regarding accademics should be included.
When you go to economic department, an adviser might be signed to you. She or he will tell you how to start in what sequence.
Normally, you have to enroll certain courses to maintain full time statue while register.
The best way to find out is to e-mail them.
There is a Chinese Students Association at OU.
OU's website: www.uottawa.ca