This is why I advise doing these short tours ...
You discover how difficult gravel roads are, and why there are those of us who make an effort to avoid any sort of gravel riding.
You discover that you can't trust online mapping programs. While they may provide you with some information, they won't necessarily provide you with all the information. Paper topographical maps might be a worthwhile investment for you if you plan to do future riding in that area.
You discover that the campground you're heading for won't necessarily have a spot for you, and that you might need to have a Plan B. You might also want to plan to book in at popular campgrounds on certain weekends in the future.
You discover that camping isn't necessarily the idyllic experience that some touring reports may have you believe it is ... it can often be a very frustrating experience.
But now that you know that and have some experience, when you set off on a longer tour, you might make some changes that would make your tour a more enjoyable experience.