Hank here from Shopify.
Offering your customers their desired currency is a huge benefit within your store, and normally changing the currency is done within the admin in Settings > General. However, once you have made your first sale, it needs a member of Shopify to assist with this.
That is when we’ll need to access your account in order to assist with this. While we’re not able to provide account-specific support via the Community Forums at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit The Help Center and log in to your account to create a support request. Once logged in, search for a topic to try to assist you with this query, and you will see the option to continue to get to the live support teams below these topics.
Once the team can gain access to your account, they can assist you with changing the currency for your store.
Let me know if you have any additional questions.
All the best,