I'd also recommend Trailer Village in the national park itself. Free shuttle bus at the door and even a pleasant stroll to the Rim.
As far as "must see attractions" - the Grand Canyon is it!! Be sure to walk down the Bright Angel Trail if only for a very short distance to get you below the Rim. You'll appreciate the Canyon and it'll give you an altogether different perspective.
For the North Rim either stay in the park or just outside the gate at DeMotte national forest campground. You'll fit in either. No hookups though. The North Rim campground does have a dump and water fill.
Each national park in the country has a wonderful web site with lots of good information on what to do, see, special park alerts, road conditions, etc. Read them thoroughly.
https://www.nps.gov/grca/index.htm