Where can I apply for immigration to Canada? How to get the file number of the embassy?

If you apply for skilled migration, go to cic.gc.ca and submit a complete set of application forms together with the application fee to Sydney (Canada) Assessment Center. After the evaluation center passes, it will send you a letter, and then submit the application materials to the Beijing/Hong Kong Embassy and Consulate. At present, the evaluation time is generally 3 months, and you can get FN within 1 month after submitting the materials. If successful, you can get an immigrant visa within one year.

It can be seen from your question that you know nothing about the operation of skilled immigrants in Canada. If you want to do your own DIY, you have to spend more time and energy.