The default currency for new events is set to euro, but you can change this in Event settings > Ticket (or Entry) categories by pressing the Currency button.

The currency setting is for your prices as they will appear on the registration form. You will receive the equivalent of that amount directly in your payment processor account, in the currency associated with that account.

Important: the currency in which you receive payments depends on your account with the payment processor you are using, not the Currency setting in Weemss.