Cabinn hotel offers you a breakfast for 75 dkr. That will say around 10€. Here you'll get fresh warm bread, koffe/tea, cheese, ham, vegetables, müsli, youghurt, sour/usual milk and some cookies.
The shower is useful but I'll warn you from my own experiences that the tap to the right on this picture regulate water from the tap or the shower. If the tap is pointing upwards you'll get water in the tap, if it is pointing downwards you'll get water in the shower. Check thia one before you brush your teeeths or using the lu. Else you'll get terribly wet.
If you go by car I suggest you use the countys parking garage. You find it in the harbour about a kilometer from the hotel. You find it on google maps>>>
You find the hotel by looking for the cathedral in Aarhus. This tower you'll see almost all over Aarhus.