I have PMd someone (can't remember who just at the moment) with "how to start up a club" so here's hoping you get it off the ground.
Our club started with someone putting an advert in the local paper asking anyone interested in keeping fish to meet at their place at a certain time and date.
We also put flyers up in supermarkets and community noticeboards like in malls, vets, libraries, scholls etc.
Decide where and when the meeting is to be, advertise and see who turns up.
From there you need to elect officers and decide which meeting night suits the majority.
If you want to affiliate to the FNZAS then it costs $5 per head plus the club pays $25 per year for the Year Books. Membership entitles members to free Aquarium World magazines and a Year Book listing all affiliated members, their details and interests plus lots of other information. Many lfs offer discount to FNZAS members too.