Your bike comes from the factory mostly assembled. Like any factory direct bike, it needs to be properly tuned before riding. If you are not comfortable assembling your bike, PLEASE take it to a local bike shop for assembly.
If you are comfortable assembling yourself below is a quick checklist and links to instructional videos.
Always have your bike properly tuned / adjusted by a qualified bicycle mechanic prior to riding. Improper assembly / tuning can lead to damage of the bicycle and/or injury to yourself. Regular maintenance and tuning is essential to ensure proper operation of your bicycle.
We have a Complete Bike Assembly Videos available for reference.
Be safe, have fun, and always wear your helmet :)
Begin by identifying the right and left pedals. Look for "L" and "R" marking on axle or wrench flats. If no "L" and "R" marking are seen, use pedal thread direction to identify pedals. Left threaded pedals (threads sloping upward to the left) go to left crank. Right threaded pedals (threads sloping upward to the right) go to right crank.
a. Heavily grease threads of both pedals.
b. Using fingers on wrench flats, thread right side pedal into right crank. Use wrench to snug pedal.
c. Position wrench on flats for good mechanical advantage. Hold wrench with one hand while holding opposite crank with other. (Pedal the bike backward to install both left and right.)
d. Using opposite arm as second lever, tighten pedal. Repeat process for left pedal, but threading pedal counter-clockwise to install.
Please be very careful installing your pedals, improper installation will result in stripping the crank arm. Crank stripping is not covered under your bike warranty.
For more information please see Park Tool Rear Dérailleur Adjustment.
Here is an example of how to assemble a road bike with STI (integrated brake lever) shifters.