FTP and how technical one needs to get to use it

I got a request to install WordPress on a server for a friend of mine. All I got was the IP address of the FTP server, username and password.

I opened my favourite FTP client Filezilla, entered the data and:

I thought to myself "can't be bothered to deal with network configuration right now" and opened my second favourite client CyberDuck. Connecting without a problem. But when I started to transfer files over ...