I am retired. My ideal traveling day is 300 miles or less than 7 hours. This includes fuel and lunch stops. On the road by 7 to 8am.
First day of travel starting a trip may get upwards of 500 miles. Mostly from excitement of the trip and to get away from weather on our winter trips.
On our way home from AZ this year. We were just outside of St Louis, MO. An easy 500 miles with home at end of trip. Should have been home by 4:00pm. But construction freeway closings and traffic jams ended with getting to our home at 7:00pm. Long day. Next day I was wasted. We have hookups at our home. Spent 2 more nights in MH before moving into house.
Be prepared for things that happen when traveling. Especially if your travels take you near large cities. Allow for travel delays.
We never make reservations during a trip. But do make plans on where to stay. But that is not always a option if traveling during times when lots of other are doing the same thing.