If your story requires input or is blocked you can start on another story that has approval.
Blocked and ‘Requires Input’ Stages
If anyone creates a blocking issue or an assignee creates a question in a story, that story changes stage. Blocking issues take the story to the Blocked stage and assignee questions to the Requires Input stage.
The move to Blocked and ‘Requires Input’ both send notifications that remain until the comment is resolved. Using an @ mention in the comment reduces the priority of the notification for all others.