Your characters can talk to anyone they want, mixing with your prospective house is the common thing to do, and you are allowed to enter their dorms and inner quads if an existing member of the house invites you in, Head Mages don't need and invite. So you can have these meetings now if you like. Like Damien can throw a mixer like an Open day/party to get more people to join Isis for example or to reinforce the bind between those already swore to Isis. First years are essentially allowed into all houses as they are all on probation, so you can make a meeting between anyone you want really.