Not sure who might be interested in this but another group I'm with are having a Beach BBQ on the 24th from 12 to 3pm. It's a BYO food, drinks and seating etc.
The reason I'm posting this is because you'll have a complete mixture of ages there from kids up to 40's especially the 20 - 30 age group. We all meet p to make friends, have a laugh and spend a great afternoon together.
If your wanting to make friends and unsure how to meet people this might be the thing for you. The website if you'd prefer to check it out is www.meetup.com. Depending on your age and interest go into young Adelaide group, outdoor lovers group, Adelaide be red group, you get the idea. They are all a great bunch of people I've meet.