You can come to Canada as a visitor. When you arrive, you will likely be granted a visit of six months. When you are close to the end of your visit, you can apply to extend your visit for another six months (note there is no guarantee this extension will be approved). You are not allowed to work in Canada as a visitor.
If you wish to work in Canada, you will need to apply for a work permit. To qualify to apply for a work permit, you will first have to find an employer who is willing to offer you a job. That employer will then need to obtain an approved LMO (labour market opinion). To be approved for the LMO, the employer will have to advertise the job and prove they were unable to find a Canadian to hire for the role. Unfortunately many/most employers are unwilling to go through the LMO process due to the amount of paperwork and waiting it takes - and because there's no guarantee of an approval. If you are able to obtain both a job off and approved LMO, you can then apply for a work permit.
Hope this helps.