We do not want empty folders, so our approach is just a bit different. Select your queries, right click and choose Move to New Folder. A new custom subfolder is created, your queries are moved here and you can rename your folder now. Whenever you move the last child object out of a custom folder, the folder is automatically deleted.
We call them custom folders to separate them from the special top folders under your database node: Tables, Views, Models, Queries, Bookmarks. You cannot move, delete or rename these special folders . Any object can be moved to another custom folder, but within the same branch: you cannot move a query under Models, table under Queries and so on. To move objects and folders under a different existing folder, select them, then drag and drop them on that folder.