Daggerfall Unity lets you map your controller in the launcher, i play it with a joystick. You can also add some quality of life stuff in the launcher.
Combat is dice rolls and takes a bit getting used to, cause you won't be seeing instant feedback while your combat skills are low. You can cheese the AI once you know when their dice rolls happen.
Save a lot, and have multiple save files, there are a lot of moments in which you can screw yourself.
Do the main quest up until you meet the spy at a tavern, afterwards, you are free to do whatever.
Dungeons are massive, never go in unprepared, yes they can take in-game weeks, even months. They are also mazes in which you can get lost easily, with tons of secrets. Even if you turn on the smaller dungeons option, Story dungeons remain as massive as they were originally.
Get a horse and a carriage to carry your loot, many times you might need to go back to the entrance just to stash your stuff.
You don't have to fight everything, some enemies are too strong, and/or require specific equipment for you to hurt them, running away is always an option.