Welcome to Shopify! I, like a fair amount of the population, suck at taxes. I tried looking around for some information and stumbled upon this: Taxes outside of US and Canada. It seems like a pretty comprehensive guide, but, on the event you still have questions, I would strongly advise for you to speak to a tax professional. Taxes are confusing at best and legally damning at worst, and the "better safe than sorry" adage is very applicable here.
Best of luck!