For free born, you definitely want bells and silks. What you could do, if it is possible, is to hang the silks from the ceiling so they are a slack and then tie things to them like the bells. You could also have vials of powder and such things hanging from these as well. You want lots of bright colours and a bit of shine.
You could also add a few contracts either in frames or just hanging down. Maybe a small wooden table and a fairly ornate drinks set. Each freeborn family have their own special drink called Syrah. What ever your version is could be in that drinks set. For storage, a sea chest would be suitable.
Maybe add something to represent glass, dust and fire, three symbols of the brass coast. The glass could be a mirror, the dust could be in the vials and then fire could be how you decorate your lights.
For seating, I recommend some cushions and such things. You want it all to seem comfortable and informal.
If you have any OOC stuff, either hide it under materials, behind other things, in boxes or chests or around the corner as if people are looking in, they shouldn’t see it. I would recommend bringing a thick blanket for one of these OOC items. The brass coast is not known for their warm clothes and such so it would be good to have something you can bring out to keep you warm at night when you are in your tent and no one can see.
I suggest you think of exotic restaurants and cafes or far off palaces to give you an idea of what you want for the interior.
What kinds of things are you thinking of trading? You could put a sign up outside your door.
I think that you may have to talk to PD about setting up and then when you do, talk to the family you are part of to see where they are setting up. If you aren’t part of a family yet, I recommend just finding out where people aren’t setting up. Either way, it might be a good idea for you to turn up a bit earlier to get it all sorted out.
(I forgot, maybe also add beads and other similar kinds of jewellery)