Hi,
When you edit a product, you can configure several prices in the Prices area and for each price, you can set a different currency.
That way, the system will display the price of the current currency to the customer.
Then, you can configure the currency switcher module via the Joomla modules manager so that the customers can switch the currency themselves, or you can use the geolocation plugin to have the current currency preselected automatically based on the IP address of the customer when they arrive on the website.