You have to select the file/folder first, then on the right hand of the page you will be able to see a list of actions including the share functionality
A Share Link is a link which you send to your friends so they can download your files/folders.
You can create a password protected link so only those who are given the password can access the resource. This feature is useful when you want to give a password to a file to a group of people.
Download managers by design, try to establish as many connections as possible to the remote server which in turn generate excesive amount of traffic. Professional and business accounts fully support downloads by download managers.
You can select the file and see the details in the properties sub-section on the right hand of the page where you can see the amount of downloads.