Grand Canyon
The Grand Canyon is a special flight rules area and there is a seperate chart published showing the routings, altitude and frequencies to use plus the routings taken by the commercial operators.
It is a great flight and well worth doing but take precautions including flight following as it is remote. You might find some rental outfits less keen on letting you out solo as a newly qualified pilot than they used to be. But the instructors are also helpful, not expensive and worth it if needed.
I would also time the flight for morning or early afternoon as I experienced some turbulence when I passed through in late afternoon.
I would second LAs Vegas North as the airport to use too. Very helpful and even produced a hire car when no one else was able to help.
I rented from Phoenix so have no experience of the operators around Las Vegas though as mentioned earlier theer are VFR routings into and out of Las Vegas North that are not comlicated but helped of course by local knowledge.