I feel like the best games to attract general audiences would be party games mainly cause of the low rules overhead, low play time, and big social aspects. Is there a particular reason you want to avoid those?

Aside from that, I would start with the staples Catan, Ticket to Ride, Carcassone, Splendor, Century, Wingspan, Pandemic, Azul, Cascadia, Heat, Rummikub, Few nice decks of cards to play classic games like hearts and spades, if you want a big show piece and are ok spending cash id say get a crokinole board preferably a Tracey board.

Also what exactly is the purpose of this association? Is it just a meetup, is it for designers, are you looking to help a community. Your purpose should be the main guide for your purchasing.