files from my computer to another computer through internet but NOT on same home network

i want to transfer files to my brothers pc without actually going there with a usb drive or hard drive, i am trying to learn about an ftp server and tried numerous times to set one up with filezilla but cant even transfer it from 1 computer to the next that are sitting in the same room while both are connected to the internet. if need be i have a tower i can entirely devote to just ftp but no tuturial i find is step by step telling me EXACTLY how to set one up. they just say put this in this box and that in that box. well it still doesnt work for a simple file transfer. i cant even figure out the whole ip address and ftp address. i dont even know how to set up a host. pretty much the only concept i get it the username and password part. i can build and fix my own computers and i just fixed a laptop that geeksquad failed to fix. but this just makes me feel dumb. i would love to send files through ftp but dont know how. help!