Setting-up international taxes for my out-of-state Shopify store

In the United States, sales tax can be affected by several factors including the location your product is shipped from, where they are shipped to, where you are registered to collect tax, item taxability and buyer exemptions.

You can set your Shopify store to automatically manage the tax rates you charge to your customers in settings.

International taxes would depend on the particular country where you are shipping the order. Different countries could have different charges and taxes, so it is hard to tell. It would be better to let the buyers know that there could be additional charges of taxes. Also, your Shopify store can calculate tax charges automatically from the settings.