music software forest

Can somebody give me advise concerning software like cubase, protools.
I like songwriting, so I have a few songs, who are finished.
HAVING A BOSS BR 600, I have probably possibilities to record music I wrote.
There are 8 tracks, and a lot more virtual tracks.Let's say, I recorded with my boss an acoustic song, but I need electric guitars too, drums, bas and voice.
The "results" of my song are stored on a compact flash card.So, probably I have to put my CF card in my PC.
RESULT: the song is on PC, I listen to it, but I hear some false notes, and I like a fatter guitar sound, and I want to multiplie my voice: WHAT PROGRAM IS AVAILABLE, and WHICH IS THE BEST TO DOWNLOAD OR BUY.
When the software is installed on my PC, I can probably look for my song, and than start to make it as perfect as possible.WHO HAS EXPERIENCE TO HELP ME WITH SOFTWARE TO MAKE FROM MY SONG, A REAL GOOD AND COMPLETE PRODUCT?
I think that there is software, cheap AND good.
Who remembers the time, even not so long ago that a program like Cubase, was almost not affordable.I am NOT a professional, but I play pretty well guitar(s), I also like playing with effect processors, the oldest is a zoom 8080, but still the best, so if I need a bas sound, I can play bas guitar in 3 different ways with that zoom, but here again, where do I plug in my zoom, can it be done on my BOSS 600?