I would put the desk perpendicular to the window, either up aginst the window or floating in the middle of the room. This allow you to look out the window and you also face the door. Shelving on wall across from desk adjacent to entry.

It's 13 ' x 12'. It has closet, an entry, a window!

Draw the space, note every wall, window dimension, closet, entrance ALL. Load it as a jpeg drawing in a comment below.

Home office like you work from home or just the household ofice needs ? Wher eis this space in the house ? What is your style ? To little info to even begin to help.

Like this? just learning, what dimension am I missing? As far as more detail this is an office for me to work from home on occassion (so home office needs) . needs a desk, chair and ideally pretty shelving for books and decor. This is a second home office so focus is comfort/style and some utility :) but printer etc are in another location already.

Like this.