You can't apply for work permit in Canada if you are on visitor visa.It's not worth travelling to Canada on Visitor Visa just to find employer who are willing to sponsor LMIA. Most employers doesn't bother to process for LMIA even they really need Foreign Workers due to process involved in LMIA application and fees and rules.Even you managed to find employers then and got +LMIA then you must exit Canada and apply work permit from your home country/place of residence or you can simply drive to U.S border and send application by Mail at Canadian Embassy in US.(You might need U.S visa or just simply go there,heard it might be possible but not sure.)
If you choose not to,then just find employers and apply for jobs from Canadian Job website like Indeed,Jobbank,Monster etc it takes time and effort to find jobs in Canada but it is better then,going to Canada and searching for job place to place or province to province.