I'm going to go ahead and expand on what has already been said by providing the locations on the site that serve the functions you're trying to create this club for.
First there is the Creative Corner. This is a forum on the site where you can "Share your short stories, poems, collaborative works, original artwork and more." there are several short story compititons there that you can go check out and participate in.
Second is the Writing Workshop. People go here to share there story ideas, and seek help with finding and plugging plot holes. You can also brainstorm ideas you've yet to fully think up. You can also get tips of how to make an idea work. Its a good way to relieve writer's block. I put my own plot up in a thread there, and I got a lot of good feedback with som good ideas on how to make my story better.
Last, but certainly not least, is The Lounge. This is where you go to just hang out and chat. As long as it isn't too spammy or too out of hand, you can talk about anything and everything here. There is a good discussion going on about dnd characters, and another about art used when someone gets banned from another site. Hell there is even a thread about bannerlord's eating utensil delusions.
We already have entire forums dedicated to what you seek for your club. These forums are split into individual threads with different topics to help with organization as well. If you were to make one single thread that tried to perform the function of 3 entire forums, it would be cluttered chaos.
If you want to participate in the forums however I would take a look at this article by Mizal, This one by ironpanther, and this one by thisisbo. the first one is forum etiquette, the second is site guidelines, and the last is information on trolls.
