There is a bus service from the South Rim to Flagstaff, about 80 miles away, but you need to ask about the times. The North Rim is about 1,500 feet higher than the South Rim. The grand total of the hike then is about 25 miles. Most people doing it opt to stay overnight at the rustic but comfortable Phantom Ranch at the base of the canyon and along the Colorado River. There, you will find a bed, a hot shower and something to eat.
Camping is also available there.
Yes, they do, but they are the rugged enthusiasts we talked about at the beginning. If you would like to stay at the South Rim overnight, Grand Canyon Lodges has a lot of accommodation there. You also can do the hike by mule train, but this article is about hiking, so we'll tell you about the mules some other time. But they probably will pass you on the way up or down. The canyon is 270 miles long, up to 18 miles wide and about one mile deep.