How to best design my new 100 square feet consultancy office? (mirror, door)

[amyhuskymom]

This is an odd room with odd dimensions.

185 Inch (Wall With Mirror/White Wall)
90 Inch (Left Wall)
46 Inch (Right Wall)
140 Inch (Entrance Door)

I will have my gym bag and gym equipment in the room as well to be stored since I am also a personal trainer.

The owner said I can do anything I want with the room.

I would like to remain as minimalist as possible as I always seem to start collecting junk and end up not being able to get rid of it.

This would be a temporary office for 1 year at most so I do not want to make it super extravagant, just presentable enough with a budget of $500.

Video of my office:
[url]https://www.youtube.com/watch?v=yJAW3W3tMRw&feature=youtu.be[/url]