greek expo

I am a transfer student who did not go through Fall recruitment at my previous school. I am trying to get some information about The Greek Expo tonight. I understand that it is not an actual Spring recruitment, but more of an informational event where the houses have tables displaying their sisterhood. I have heard that some of the houses with available spots might offer invitations to their houses to see if you/they are a fit. I also know that just because a house may have available spots does not mean that they can/will fill them. My questions are will ALL of the houses have tables at the Expo tonight and which houses (if any) actually have spots that they are allowed/willing to fill? If it's only a few, assuming that I was lucky enough to even get an invitation/bid, I think I would prefer to wait until Fall recruitment so that I can get the opportunity to see what all of the houses have to offer. I want every opportunity for my greek experience to be successful. Thanks