At this point, you should have a menu item for your newly created downloads view. However, if you click on it, you will see the "Downloads" title, and nothing else. Let's go ahead and add some sample content.
Go to Create content->Download. Enter a title for the download, and give it a description. Under "File Name," browse for the file you want to add, and upload it.
Save the new entry.
Now, if you go to the "Downloads" link from the menu, you will have the node for the file you just added. At this point, it doesn't look too bad, but we can do more with the appearance to make it look similar to DOCman. If that's something you're interested in, keep on reading.