1 . since it is a new bike yes take it in and have the shop look at it. For most shops the first tuneup is free ,it the breaking in period and cables do need adjusting.
2. to do this yourself, you need to shift to the smallest gear (granny gear ) in the front and the largest in the back (low gear) now adjust the low (L) screw until the you eliminate the chain rub on the backside of the cage. now shift to the small gear (high) in the back and the large one in the front and adjust the high (H) screw to eliminate the rub on the front side of the cage. now take the bike out for a ride and do any minor adjustment with the cable adjusters.