Hi AcctDev,
You are able to practice Dynamics 365 for financials after getting start free trial from URL blow.
https://www.microsoft.com/en-us/dynamics365/financials
click 'Get started' and enter work e-mail and phone number on next page.
Now, 'Dynamics 365 for financials and operation business edition' is the latest version name of D365 for financials.
Best regards,
Shinichi