While we do not support deleting at the moment, you can achieve the same effect by archiving the questions by clicking into the question. After clicking into the question, you can toggle to Archive/Publish the question:

Setting the toggle to "Private" ensures that only the admin who is logged in can view the question. Members of the public will no longer be able to see the question.

Alternatively, you may also edit the question and change the "Answer status" field from Public to "Private".