Which OS image did you select when creating your droplet?
I selected Wordpress on 14.04
Have you installed and configured a web server?
Yes (I followed one of DO tutorials on YouTube), I used PuTTY, entered "root" as login, changed the password. Then I typed the IP address on my browser, they asked me to log in, I typed "admin" and the password PuTTY gave me, and got a blank page
When uploading (I assume via SFTP) what directory are you uploading to?
I did not upload anything yet. But I tried to upload my WAMP database via FileZilla 4 days ago and it didn't work because I kept getting 500 Internal Server Error (I didn't see the "It works" page neither the first time I tried). I reinstalled WAMP and started all over again.
Also... I don't use any SSH key, I've read that it's a way to secure a website but I don't know ANYTHING about buying or installing an SSH key. So I just use WAMP, PuTTY, FileZilla and DO. Maybe that's the problem? I'm sorry if I sound naive or anything, I'm just super new to all of this, and when I should probably hire a developer I just want to learn by doing these things myself.