I wish you the very best for your new guild. I am the member of one guild and would probably be a serial guild attender if I didn't still have a child in school and there were more daytime guild meetings available. My guild added a daytime meeting a little over a year ago and that has worked out beautifully for me. With the daytime guild I have made it a point to try and greet everyone, learn their names and ask them to do something. There is always a general need for help on various chairs or committees, but asking someone directly seems to be a better approach.
Games: Our evening guild plays Quilto once a year and our daytime plays sewing box scavenger hunt once a year.
Challenges: The ones with a "carrot" of fabric seem to be the best participated in. Secondly, a meaningful topic idea also seem to generate many participants.
Silent Bid or Montly Mini Fundraising: Small quilted or quilty item valued at $15 or more.
Show and Tell: Of course! This is what many come for. We actually moved this before the speaker so it didn't get pushed to the bitter/late end of meetings.
Try: Make and takes, something that can be made in less than 45 minutes. Skills Rounds, have three different people demonstrate a skill or differing versions of a skill and then rotate groups every 20 minutes. Try a fun way of mixing the audience before you start to allow the opportunity to meet new people.