You need a valid job offer as well as meet the requirements of the stream. You can read all about these here:
https://www.ontario.ca/page/oinp-employer-job-offer-foreign-worker-stream#section-1 Note that this stream is about to undergo significant changes, so all of this could be out of date soon.
Generally speaking, I believe most of the outland candidates in this thread are working for companies who have offices in Canada and are transferring. For myself, I was already in and working in Canada and asked my employer to sponsor me. Getting an employer to sponsor you in Canada, without having worked for them previously and not being physically located in Canada yourself is going to be incredibly difficult.
Depending on what your country of origin is, I would suggest looking into alternate ways to start working in Canada (Working holiday, LMIA, etc) these can range from easy to hard in difficulty to get approved for and will get you closer to PR.