Do I need to renew/transfer my canada visa or can I simply travel with
valid visa on old passport?
You don't need to transfer your valid Canadian visa on your fresh passport. You can simply attach your old passport with your new one and can travel to Canada. Answer is from official Immigration And Citizenship EN4 Port Of Entry Examinations:
13.18 Valid visas in expired passports
Visa officers will not put a visa in an expired document and will not
issue a visa for a period surpassing the expiry date of the passport
or travel document. Occasionally, documents containing valid visas are
cancelled or replaced. If a valid visa inside an expired document is
presented at the POE along with a valid passport or travel document,
the visa is considered valid.
Therefore you will be fine and can simply travel to Canada with valid Canadian visa on old passport along with a valid new passport.