If you ever wanted to learn how to read a map and be able to plan and execute a cross-country adventure with naught but said map, a ruler and compass then allow me to introduce you to LANDNAV.

While there are similar games and tools, none of them offer it either as seamlessly or as detailed as LANDNAV does.
Currently, there is one location, though the game has a few dozen 'exercises' across 3 different difficulties, this alone is the best crash course one can find on a computer. Moreover, the whole range is available at all times for you to get lost in or explore; Creating a virtual sandbox for you to test yourself, and your abilities.

The game was largely built around military land navigation courses, though this has few practical consequences, the largest is the format of the game's 'exercises', reflecting how land nav is taught and trained in the US Army.

Don't let this scare you off, if it wasn't for the character being dressed in camouflage with a rucksack and rifle it would be easy to miss the military influence and the game shouldn't be overlooked for it.

If the military format and style are a deal breaker for you, there is an orienteering-focused (free) update in the works so it may be worth wish-listing and checking out later.

Lastly, there is an official discord. If you want help or advice with learning land nav in-game or in real life it's a solid resource with a welcoming community full of people happy to share what they know.