Major Version Differences

Fire Emblem Fates is composed of three different versions. Basically, it's three games with interconnected storylines. Each version is considered as an entirely different file. That means your character level, skills, relationships, and everything including your castle progress, design, or data will not be carried over if you start a new save in another route, even if you have the Special Edition (all three versions in one cartridge) version of the game.

Here are the version differences which can help you consider what path you should take first.

Birthright

Recommended for first gameplay

• Farming gold and experience can be done outside the story mission through skirmishes known as "Challenges". Players can get new items, gold, and weapon proficiency boosts from these skirmish maps.
• This path has the Scout option which will unlock new skirmishes on completed maps by paying a minimal fee. Higher level maps require more gold to enable skirmishes.
• Quest objectives are very straightforward like defeating (routing) all enemies or defeating the boss. There are no turn restrictions as well.
• My Castle has only Hoshidan Buildings and Facilities.

Conquest

Recommended for second playthrough, after Birthright.

• Experience and funds is very limited. There are challenges but there's no Scout option.
• The only way to farm gold and exp is by purchasing extra DLC maps (Ghostly Gold and Boo Camp) These maps are scaled to your party's average level so you can farm here anytime you like via Dragon's Gate.
• More challenging mission objectives like limited number of turns, breaking through a blockade, defending a position, etc.
• My Castle only has Nohrian Buildings and Facilities

Revelations

Since this path offers insights from events of Birthright and Conquest, it's recommended to play this last.

• Challenges are present, similar to Birthright
• Missions will have various conditions similar to conquest
• Classes from both sides are available
• My Castle has access to both Hoshidan and Nohrian Buildings and Facilities. Four resource nodes will be available as well.