Firefox is free and it willl work.
Copyright is not hard. No need to pay a service. Just go straight to the Library of Congress website, follow the instructions and pay the fees.
You can legally copyright up to ten songs in one application, if you are the sole author. I've done that a couple of times.
I submitted a single .pdf file (export from Word or Open Office, easy) with the lyrics and chords and a single MP3 in MONO with amended simple demos of all songs in the same order as the .pdf.
By amended I mean there is no need to repeat the chorus more than once, for instance. If the third verse is the same as the first, that can be omitted as well. Mono keeps the file size under control and is all that is needed. Don't worry about quality, if a lower quality MP3 is clear enough, it's good enough.
I titled my submissions "The Works of Kuru Prionz, Volume One" (and Two). I did use my real name, the same one the copyright is under.