Hi, and welcome to the forum.

Toronto is a really nice area, though it can be a bit expensive, depending on your budget and your lifestyle.

For immigration purposes, it helps to know what kind of work you do. Sometimes it can be easier (relatively speaking, that is) to get a visa if you're in a particularly needed type of work. Also, Canada is a big place and some types of jobs are more available in specific areas or provinces.

And all that figures into whether or not using an agency is worthwhile. If you don't have a claim on a long-stay visa, an agency can help you find your best shot. If you are eligible on your own, you can save the fees by doing your own paperwork.
Cheers,
Bev