What are three specific changes that take place in Roaring Camp after the birth of Luck?

The changes to the camp emanated from Luck's arrival there. First, the town decided to spruce up the cabin where Luck lived: "It was kept scrupulously clean and whitewashed. Then it was boarded, clothed, and papered." When one place starts to look nicer, the surrounding places look worse, so people will naturally start to spruce up their places. As such, Tuttle's grocery installed some new carpet and mirrors.
The next change was in the personal hygiene of the campers. Because Roaring Camp was a mining camp and its inhabitants mostly men, personal hygiene was not of the utmost importance. But, because Luck was a baby, Stumpy (his guardian) would not allow anyone to hold him unless that man was clean. Kentuck, a man who on the outside would seem the least likely to care about a baby, would not allow his slovenly appearance to keep him from the baby, so "he thereafter appeared regularly every afternoon in a clean shirt, and face still shining from his ablutions."
Finally, because Luck was a baby, the camp needed to be quiet so he could sleep:

The shouting and yelling which had gained the camp its infelicitous title were not permitted within hearing distance of Stumpy’s. The men conversed in whispers, or smoked with Indian gravity. Profanity was tacitly given up in these sacred precincts, and throughout the camp a popular form of expletive, known as “D—n the luck!” and “Curse the luck!” was abandoned, as having a new personal bearing.

Music was still permitted, because it was thought to be lulling to the child, who would fall asleep to "Man 'o War Jack" singing him a sailor's song that soothed him to sleep.
The town was being changed, inside and out, because of the arrival of this one child.