Another vote for RV Life trip wizard. You get a visual map with links to campsites, some key data about each one when you click on it, overall ratings from travelers, and a link to their website to book it. Once you save it as a destination you have the whole route to follow.
When planning, I usually have another page with google maps on the side so I can easily see the roadmap and route options, as well as distances.
I have also found Chatgpt to be very helpful to turn my general travel ideas into an actual route with both sites to see and campsite recommendations.