I am not very familiar with the specifics of registration, accommodations, etc. However what I would recommend is that you email the race director and let him know that you want to align with the DCTC so you can gain the benefits and be racked with them, etc. They should be able to rectify this situation or direct you how to do so.
As for accommodations, I have no idea what the club does here. I know they organized a pre race dinner. But I don’t remember anything about accommodations. I would go ahead and find something in advance if you want to sleep in a bed before your race. Nice work planning ahead all!