A couple of possible options.
Hello and welcome to the R.T.A forums.
To cross Death Valley I would head North on the 395 and then head East on the 190 through Death valley junction to Pahrump and 160 to Vegas. It will be a long day but give you a great overview of D/V, passing the Sand dunes nr Stovepipe wells, Furnace creek and some nice view points along the way. Get an early start and it's worth it I.M.O.
Your other option to experience desert driving would be a detour of I-15 through part of the Mojave national preserve, with a possible side trip to Calico ghost town just outside Barstow.
Details of the detour into Mojave n.p.