Do you know when you reached member status? Sometimes the system takes a bit to recognize this. Try signing out and sign back in.
Click on the events page itself and try creating one from there
Log out and in again
As stated, just wait a bit and you should be good :) Or for now you can create one and then get someone to change it to the category :)
Wait a little bit or sign back in. It happened to me when I became a member