What type of Canadian visa should I apply for to attend a conference and tourism in Canada? Is it a work visa or a visit visa?
The type of visa you need is the same regardless of whether you go for business, tourism or transit. Canada calls this the temporary resident visa. You may choose business while applying for the visa, and you will receive a temporary resident visa which is good for all of these purposes.
Your primary visit is the conference, so get a work visa, you can then use this to conduct tourist activities.