Study Abroad

If your profile is otherwise great and your performance in GRE too, then work experience may not really add to it. Getting good recommendations from your professors, transcripts from your University is likely to be easier while you are still in college. The more time you have been out of college the higher the probability that your professors do not remember you as well. Off course some times that could be an advantage. A weaker profile could however get some help from experience in the same line of work or even from working in a good Company in a related field. But unless you have actually worked in some cutting edge technology the difference it will make is marginal. On the other hand if there is a gap of a few years and you have nothing to show for it, it definitely could go against you. University admissions in top notch Universities is generally more about rejection and less about selection. In general, 1-2 years of work experience is helpful
But if you have a stellar profile without a work experience too, and are sure you want to do MS, then there is no NEED as such for work experience. Hope this helps you. Be free to share any problem you have.
Good luck.

Yes, of course, you can apply for Canadian universities. And yes, you can also appear for SAT exam.
SAT Eligibility 2018: Key Features
Although the College Board does not prescribe any particularSAT 2018eligibility criteria, students aged between 17-18 years of age mostly appear for the SAT 2018 test to get admission into colleges for undergraduate studies. Ideally, high school students opt for the SAT examination. Age Limit- SAT eligibility 2018 do not state any age limitation to appear for the SAT test. If a candidate is 12 years old or younger, he/she can register for SAT by mail ONLY. If a candidate is 13 years or older, can create the free College Board account to register for SAT 2018. According to the SAT 2018 eligibility, if a candidate is 21 years or older, then he/she must produce an official government-issued photo ID, like a drivers license or passport, to the test centre. Hope this helps you. Be free to share any problem you have. GOOD LUCK.