Follow these step by step methods to upload your file and get link of that file
a) Go to www.dropbox.com and Login with your DropBox account. If you have no account, first complete signup process and then login to your dropbox account.
b) Click file on the left sidebar and upload your file into your Drop Box Window.
c) After upload process completion write click on that file and click Share.
d) Now you can simply copy that link to share