I was reading the forum rules and it said something like I have to wait 14 days to post threads in workshops, but I don't know what workshops are.
The workshop is a place for you to actually share your writing so that others can read it and give you feedback and constructive criticism.
Th general creative writing forum is for questions, discussions, things like that - not actual excerpts (well, small ones if a specific phrase or something is giving you trouble, but not much). In the workshop you can post short stories or chapters from novels and so on for people to read in their entirety.
Apparently General Writing is swamped with misplaced things that should be all over the rest of the forum. They're even considering moving it to the bottom of it's category so people have to read some other sections before hand, increasing the chance they put it in one of those. I also think it would be improved if people looked at this; https://www.writingforums.org/threads/new-member-quick-start-guide.132102/, before going anywhere. (Yes, I am using this opportunity to introduce you) Welcome to the madhouse!
It might also be worth mentioning that the Writing Workshop is the only place on the forum where we allow members to post their work.