Kassey here from the Shopify Guru Team! Usually, as the merchant, you would only charge taxes to the province/state that you're selling in, but to provide some more context - I would recommend taking a peek at the Should you be Charging Sale Tax Shopify guide!
When setting up your taxes section from your Shopify admin, you will want to follow the guides in this helpful Shopify doc. But be sure to ask a financial professional or a tax professional near you to double check on what you should be charging for taxes!
I hope this helps, but if you have any further questions - be sure to reach out to Shopify support!
I'm building a store to be operated from Australia. What I understand is you only need to pay taxes when you start making some income(not sure of the limt) from your business. And GST is applicable only when you have turnover in excess of 75k. So, for launch we can leave the tax section blank. This is my understanding. However, appreciate if you have got some other info on this and can share it.