The throttle cables usually have an adjuster part way done the cable & at the throttle bodies but it more than likely needs the tank lifting off to get at the adjusters.
If the bike is new it is something that should have been dealt with pre-delivery & during the 500 mile service. Make sure they have done all the other checks & lubes on the bike, otherwise complain :rant Your safety relies on the dealer giving you a properly adjusted & prepared bike.
are you guys for real?! there are throtle cable adjusters right at the grip pretty much. You don't need to remove the tank! There will be 2 cables goin to your throtle, about 2 inches down the cables from the girp (behind the master cylinder) there will be adjusters. There will be just loosen off the long threaded adjuster until your satisfied with the play in the grip, then tighten the lock nut. Make sure u adjust both cables. One opens the throtle, and the other closes the throtle. You will need to do this every once and awhile as the cables will stretch over time.