@Laylwwa I made some long journeys - you may have a look at my blog here.
At first, I'm planning the whole journey - simply entering Via Points for all sight seeing stops, or major accomodation, etc. to see the total distance. By my many years experience, I divide the total distance trough 350 Km (for each day) = needed days in result.
Later, I decide highways, scenic roads, or offroad sections I will drive on. If more offroad, if less possible distance!
On highways (at boring areas) I plan max. 500 Km/day.
Smaller roads - with little sight seeing, or photo stops - I plan approx. 250-350 Km/day.
Offroad - with little sight seeing, or photo stops - I plan approx. 150-200 Km/day.
It depends on road type, traffic, season time, weather conditions, possible gas stations, possible accommodations, your flexibility, your capacity of pain killers, water, fuel, food, or fresh clothing.
Sometimes, I do reservation in Hotels at forefront. Advantage is: you will get what you want; which is nice and luck. Disadvantage is: you may need to hurry, if you planned a too long distance; which can be stress.
Sometimes, I do no reservation in Hotels at forefront, but try to find an accommodation just in the afternoon of a day. Advantage is: you don't need to hurry. If you are tired, stay and take a hotel. Disadvantage is: you need to take whatever you can find locally. But sometimes, there is no Hotel next to you! Or they are overbooked! Or season is over and they have closed! Which can be stress and painful.
For longer journeys (more than a week), I usually plan 1 day off (don't ride, don't walk, just relax) every 5 days!
You see: it depends on many things, but not on the app you are using for route planning or navigation 😉