Congratulations to you. May I suggest that you really try to visualize yourself in the room and put the furniture in it's place before you fill it up. Get a chair, sit where you think you'll be sewing, dream and pretend. Stand at the door and think about where you're putting furniture. Put a piece of paper on the floor (as big as it is) so you can SEE it.
I think it would be a whole lot more work moving the stuff again after you just finished putting it in it's 'temporary' place.
You're going to have to treat yourself like a parent
"clean your room then you can go outside to play"
"organize your sewing room then you can PLAY"
:) LOL - can't wait to see pictures