San Diego to Vegas for not very good driver

Hi,
I've got tickets to fly into San Diego mid Sept and fly out of Las Vegas a week and a bit later. I have a US and UK driving licence, I have most experience of driving in small cities in the US (mostly coastal Carolina) but haven't driven for a year anywhere so am a bit nervous. My plan is for me and my boy to share the driving on a trip (he's more confident, if about as experienced with driving as me). My plan was to spend a few days in San Diego with mates then head off of a trip.
I was trying to split the drives up a bit and wondered if this seems an ambitious itinerary:
Drive San Diego-Joshua tree area and spend the night
Drive San Diego-Vegas and spend 2 nights
Drive Vegas to Death Valley and spend the night
Drive Death Valley to Laughlin/Kingman and spend the night
Drive Laghlin to Grand Canyon (South Rim) spend the night
Drive GC to Vegas

I was wondering how much of this would involve having to drive fast on big highways (boo) and how much on roads that would be scary in general. Or if there were any roads that would be good to use/avoid? And also if this looks like a realistic plan.
Thanks for any advice!

Welcome to the RTA forum!

I'd say the main places where big city traffic would be a concern would pretty much just be in San Diego and Las Vegas, and maybe a little bit of a concern as you hit the edge of LA Sprawl on I-15, but the places you've listed shouldn't be too problematic.

I really wouldn't worry about "big highways" that much. The interstate system really is much safer and easier to drive than 2 lane roads, but I don't see either being too much of a problem here.

What I would say is that you've got a very bizarre route laid out. Its kind of a "figure 8" and if driving is a concern, it will put you in a car far more than you need to be. I would go from Joshua Tree and continue heading out to the Grand Canyon, without going all the way north to Las Vegas. Then go back to Vegas, through Laughlin if you'd like, and then do Death Valley as a daytrip from Vegas.