I'd go north on I5 and take 99 to Sacramento. Then take 80 into Reno.
I suggest that route for a couple reasons.
In case you have problems you are closer to help along that route. Lot's of RV repair places on 99 and Sacramento.
99 is in pretty good shape now, just went that route two weeks ago.
It's all four lane road and you want four lane until you are more comfortable driving on small roads.
I don't know if you are familiar with mountain driving. You will be when you are done. You will hit two mountains...The G****vine and Donner Summit.
The most crucial thing is to go SLOW down the mountains. I just went over Donner twice last month and never exceeded 45 mph. Because it's four lane the people can go around you.
I used to pull a 91 Miata. You won't know it's behind you as they only weigh about 2,200 lbs.
