Student or Learner
I'd like to put up a poster in my waiting room to make sure people don't enter my office before I invite them to do so....
Does the following sound right please?
"Have a seat please, we'll come and see you very soon".
It's OK though I would separate yours into two sentences rather than with a comma. You'll see "Please take a seat and we will be with you very soon" or similar too. Maybe "Please take a seat until you are called into the office" would work too.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.