Street bob 2015 ticking ?
Being new to Harley bikes explains a lot. The sound an air cooled, pushrod, vtwin motor makes at idle may take some getting used to. Having said that, there have been issues with the "C" type lifters used since the '10 or '11 model year; forget which year the "C" lifters replace the "B" lifters and outsourced the manufacture to Mexico.
As has been suggested, I would go on record with the dealer at the first service and continue listening. If the noise increases, take it back to the dealer so there will be a record of the complaint. I doubt that the dealer will consider the noise your are hearing as abnormal and you will get the "they all do that" response. So establishing a record of the complaint might help in the event that there is a problem in the future.
But until that happens, ride the bike and the noise will become less of an issue the more you ride the bike and associate with other riders, listen to other bikes and are no longer "new to Harley bikes".








