How do I make a floor plan with specific dimensions? This is my very first time of using blender. I've tried several tutorials but can't find anything that tells me how to do the very basic thing i want to do.

I simply want to draw a floor plan for a room which is 13 feet by 11 feet and make it 3d so that ultimately i can play with where things go in that room.

Can anyone take me through the steps needed to do this? 

I will be so grateful.

Thank you in advance
First delete the cube and add a plane. Then go to the Scene panel and set units to Imperial 



Then go to the Properties panel and enter 13 feet for x and 11 feet for y value like below



Make sure apply the object scale with Ctrl + A so further transformations don't get distorted