Welcome Anthony!
We get together 3 times a year: Jan/Feb for a seed swap, May and Sep/Oct for a plant swap.
We use the 'swap tool' here on the NGA site to list plants that we have to share. Participants call 'dibs' on posted items. We meet on the announced date and location to swap plants and have a pot luck lunch.
We you say you are new here, do you mean to the National Gardening Association, or the Mid-Atlantic group? Knowing which will help us explain in better detail.
Our next swap is on Saturday, May 19.
To get an idea of what people are offering, check out
https://garden.org/apps/swap/swaplist/22/