Go ahead, you’ll be fine.
If you want to test first, create a new resource group and some new resources. Add them to the group, then delete the group. The resources will survive.
Note, though, that if you delete a container document, its children will be deleted too (but you’ll get a warning first).
As further reassurance, deleted resources remain in the tree until you delete them by clicking on the little garbage can. Until then, they can be undeleted at any time.
