Simple way to create a 2d game?

I’m new to unity but am learning fast!
I was just wondering if anyone could help me a bit on the way.
I was thinking to create a game like “Desktop Dungeon” in the way of art and play style.
Overhead game oriented by arrows and no moment at all except from the player image.
Where should I begin?

I was thinking of beginning with one simple level, like on dungeon and with already placed enemies. Just make it simple you know.
Should I make a picture of a dungeon and put it in a layer and then have the main camera just above the layer and then make pictures of the player and the enemies?

Begin in the forums, not this dev-tech Q&A board. Look in the Asset Store for things that will help, and read the docs.