How to change gears/speeds on my new road bike.?

Recently I purchased GMC Yukon XL road bike.

http://www.amazon.com/GMC-Yukon-XL-Road-



It came semi assembled. I installed the front wheel, seat and handle. Ready to go but I was unable to change speeds. I used the levers next to the brakes but see no difference in my driving experience. I am sure I am missing something. The speed controls and brakes are pre-fitted and I did not replace any thing. Please helpHow to change gears/speeds on my new road bike.?
Right-hand shifter:

The little thumb-tab on the inside of the shifter body shifts you to a HIGHER gear.

Pushing the brake lever inwards shifts you to a LOWER gear.



Left-hand shifter:

The little thumb-tab on the inside of the shifter body shifts you to a SMALLER chainring.

Pushing the brake lever inwards shifts you to a LARGER chainring.How to change gears/speeds on my new road bike.?
i have a road bike, and on the handle bars are knobs with numbers on it. on the left on, there are 1-3 and on the right 1-7. The lower the number the faster and the higher the slower. i dont know if this is how your bike works, but i hope you can figure it out! good luck!
Read the manual.
Is the chain on the bike?



Are the derailleur cables attached to the shifters and the derailleurs themselves?



Are you riding the bike while attempting to change gears? They won't move unless the pedals are spinning.