Which part of the canyon, realistically
Grand Canyon West, which includes the Skywalk glass bridge, sits closest to Vegas and is the most realistic option for a single-day trip by road or air. The canyon's more famous South Rim (Grand Canyon National Park) is considerably further and generally needs a longer day or an overnight to see properly.
Tour vs self-drive
Organised tours (by bus or small plane/helicopter) handle the logistics and are popular for exactly this reason — the distances involved make a guided day trip genuinely convenient. Self-driving gives you more flexibility if you'd rather set your own pace, provided you've budgeted realistic drive time each way.
What to bring
This is still desert terrain — bring more water than you think you need, sun protection, and layers, since temperatures swing sharply between day and night even when Vegas itself is mild.