Congrats on signing up for your first race. Likewise, I am doing my first race this Saturday...a 2-man 40km TT. My partner is a triathlete. His training uses a taper period 1-2 weeks out from the race period, where you cut your distances, but not your intensity.
I have been on a taper period for about a 2 weeks. I did a dry run of the TT course 3 days ago, and found that I was able to ride well above my LT for extended periods, and could recover at higher heart rates. If this is a result of the taper, then I'm sold on the concept.