Ok I just switch from a pc to a mac. I installed dropbox from the website and it shows it's in my applications and in my launch pad but when I click the icon it won't launch. I then tried to uninstall it and it doesn't give me that option when I have all my apps wiggling in my launch pad. So I then researched on how to uninstall and I found that I can pull up finder and drag and drop the application to the trash. When I do that I get a message "The item “Dropbox” can’t be moved to the Trash because it’s open.". So then I try and force quit Dropbox and it isn't listed to be forces closed. So I am assuming it isn't running? Help I just want it off my computer. I don't like items on my computer if I don't or can't use them.
Info on my Mac
OS X Yosemite version 10.10
Please remember that any help that is given I need step by step instructions. I've only had my mac for 2 weeks and I am still learning.