Yes, guitar music is notated an octave higher than it sounds. That's because the guitar is rather a low pitched instrument. It's notated an octave higher so that its notes can be conveniently written on the treble staff. If written at its true pitch, most of its notes would be too low for the treble staff and still too high for the bass staff. So notating it up an octave was a workable solution.
If you play piano or violin music directly from the score, it will sound an octave lower than it should. That doesn't bother most people though. If it bothers you though then, yes, you'll have to take it up an octave into "no man's land" on the fretboard (Good phrase - I must remember that)
