Patrick,
That piece is in the key of A and I didn't see any accidentals in a brief glance. The difficulty in the music is that it is written for piano, where there is a chord change very frequently. Classical guitarists make these changes easier than we rock folk. There are two options, I think:
1- you can simplify the chords on the attached page, but you will have to alter the melody in areas you simplify to match the chords you are actually playing or
2- see if you can find the song in guitar tab online, where someone has done that for you.
I could go through it, but someone like Tim Foster could do it better and faster. It is very difficult for a guitar to chord change every note, sometimes in complicated ways, and make it sound fluid, then sing along......