Yes: it is correct if your intent is to sell the whole contents of your "Stuff to sell" listing folder as a single product. If, however, you wanted to sell your "stuff" as a collection of different products, you must have one listing folder for each product. The usual way of creating a new listing folder is to copy an item (a boxed product, usually) or a folder (for non-boxed products) from somewhere else in your inventory and paste it into the "Marketplace Listings" folder (a drag and drop action also works: simply drag & drop the item or the folder).
On creation of the listing folder, the viewer automatically creates a "version folder" (that folder with horizontal lines in its icon) and pushes all the items into it: later on, you will be able to add more version folders into that listing folder, but only one version folder may be active (i.e. sold) at one time on the Marketplace.
If you correctly read/view/follow the tutorial, you will notice that before activating (=listing) any listing folder on the Marketplace, you must first either associate an existing "Marketplace listing" to the "listing folder" (this was used for migrating old Marketplace items to the new VMM system, and may be used if you accidentally deleted a listing folder and want to re-associate a re-created listing folder with the old Marketplace listing), or create a new listing on the Marketplace for your "Stuff to sell".
To do any of the latter, simply right-click on the listing folder (not the version folder), and pick up "Associate listing" or "Create listing" (before creating the listing on the market place, you might want to rename the listing folder to the exact name you want your product to be listed as).
The first option pops up an input floater for you to give the listing number, while the second option directly creates a new (incomplete) Marketplace listing page (the listing number will appear next to the listing folder name).
In the second case (creation option), you must also Edit the newly created listing on the Marketplace in order to be able to activate it later; simply right-click on the listing folder and choose "Edit listing", which opens a browser (either internal or external, depending on how you configured the viewer for browsing) pointing to the Marketplace listing form which you must duly fill-up and validate.
Once the Marketplace listing page associated or created/validated, the "List" option will become available in the context menu of the listing folder.
If, later on, you want to replace a product version with another, you may copy/paste (or drag/drop) the new item/folder representing the new product version into the existing listing folder, and you will then be able to "Activate" the new version from the version folder context menu.