Others have posted good advice.
When driving our Class C it is rarely over 60 MPH,
saves gas, makes wind buffing from trucks and mother nature easier.
Enjoy your trip. Do not let others on the road push you, it is your rig.
I look at 8-10 hours as my usual max drive.
I usually leave early, especially the first day, trying to plan where I
will be for expected "morning rush hour" and parked by the "evening
rush hour" when possible.
One good piece of advice I read was the 3's.
300 miles and parked by 3PM, some also add stay 3 days.
Try to relax and enjoy the journey.
We make the journey a major part of our trips.