Power BI groups do not require an Office 365 subscription! If you do have an Office 365 subscription, you get to take advantage of extra features like connectiong to a group's OneDrive account, but without a subscription, you can still create and manage groups and connect to the other data sources.
@Amanda since I do have an Office 365 subscription I can't really test it out, but... is there a way to delete a group if one does NOT have an Office 365 subscription?
The only way to delete a group that I have been able to find was to use the Office 365 Admin portal.
I have the delete group button available...I've already used it several times.
BTW, there appears to be a name length limitation on the group name, but it doesn't generate an error. The process that creates the OneDrive folder locks up. My computer spend all night telling me that it might take a while. I tried several variations on the name, but finally shortened it, and it worked.