Welcome to the Community, markacarey.
Trading in Euro is unavailable in QuickBooks Self-Employed. The multi-currency feature is only available in the regular version of QuickBooks Online (QBO).
You can check out our website for a detailed comparison of products: https://quickbooks.intuit.com/uk/pricing/.
Additionally, I'm adding these resources to know more about how multi-currency works in QuickBooks:
About Multicurrency.
Learn about Multicurrency in QuickBooks Online.
In case you need help with categorizing your transactions in QuickBooks Self-Employed, you can refer to this article: Categorise transactions in QuickBooks Self-Employed. This will help guide you on how to report your self-employed income and expenses.
For more questions about QuickBooks, feel free to drop me a reply below. I'll be around to provide additional assistance.