You need to secure a job offer from an employer in Canada and then that employer has to obtain something called an approved LMIA. You can then apply for a work permit. There are no jobs or employers here. You will need to apply for jobs through websites such as linkedin, indeed, etc. It's generally very difficult to find a job in Canada. Be careful of job scams. If anyone asks you for money, the job is fake.
You can also see if you qualify to apply to immigrate to Canada directly without a job offer. See the Express Entry program below. This is a points-based program and you want to have a score of 480+ to have a good chance of being selected.
I immigrated to Canada about ten years ago and work in software. I would suggest Seattle or another west coast city for tech.
Tech salaries in Canada (Vancouver) are very low and house prices are insanely high. My wife and I are definitely top 5% of earners and can barely afford a place (we have no help from parents on either side).
If you do come to Canada, work for a US tech company, they pay about 50% more than Canadian tech companies (maybe except Shopify).
I'm more and more considering Seattle. My salary would about triple and housing costs would significantly decline.
Sure there's healthcare in Canada but if you're working in tech in the states, you'll get it at most tech companies.