I would say you're retarded.. but you're only 15 and don't know much about cars..

the
SEARCH button is your friend.
Sounds to me like you're explaining you're transmission downshifting then upshifting again. It's normal for an auto transmission to downshift to a lower gear when you step hard on the gas, it will then upshift back to the higher gear after its reached the shift point.
Regarding the OD button. Your automatic transmission has 4 gears, if you drive with the OD button on, you will use all 4 gears and gas consumption, specially on the highway will be good. If you drive with the OD button off, you're only using 3 gears. Which is normally good for city driving, but most people drive with the OD button on all the time anyways.