Don't be getting too excited!

Some of the Eurovelo routes, or sections of them exist as ideas rather than reality.
I've been on some of them for parts and they can vary from country to country or from region to region within the same country.
In reality, a lot of EV routes are actually connecting individual national cycling routes.
In places like NL, Germany, France that might mean a decent amount of dedicated cycle paths, in other countries more road, albeit generally quiet. There are no hard and fast rules with EV routes. If there's any off-road it will be suitable for nearly everyone.
One problem can be getting gpx files of the routes, if that's your thing.
https://www.biroto.eu/en/ is a good source for long distance European routes and national routes.
And
https://cycle.travel/map is the best planner in my opinion.
For more reading and inspiration on long, cold winter nights there's
https://www.crazyguyonabike.com
A treasure trove of journals and a really good search function.
Good luck!