The Grand Canyon is a must see. You will regret it if you never get to experience the expansive landscape. Multiple visits are not rare and most visitors start in Phoenix making the scenic drive 2 hours north on I-17 to Flagstaff. Some stop for a night in 3,000 feet Sedona to adjust to the rising elevation from sea/desert level. A long weekend is just enough time to spend wandering the galleries, nature trails, and wine tasting your way through norther Arizona; a full week would be better, but it will also make you seriously consider retiring in the area.
The Grand Canyon Railway is another way to get there from nearby Williams, AZ. Prices vary depending on dates and party size, with coach seating starting at $75 round trip. Hotel rooms are adjacent to the both the Williams and Grand Canyon depots. The website (below) is easy to use and provides more information on train service.