2 weeks ago i had a partial thyroidectomy they said it was cancerous but won't be making any decision of what to do til 14th jan is that normal?

Often yes: Most types of thyroid cancer grow slowly over decades, so these are typically not emergencies. Additionally, your cancer team is probably waiting for the pathologist to make a detailed report of the specimen to determine what kind of additional therapy you do or do not need.

Not unusual: No undue risk of waiting a few months even, to make decisions.