If you don’t currently have game time added to your account, the sub forums it lets you post in are severely limited. If you have recently added time to your account, it can take up to 24 hours for the posting restrictions to lift.
If it’s been longer than that and you still don’t have posting privileges, changing the password on your account can jump start the system and get things set straight.
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As for the guild question, I’d suggest checking out this thread at the top of the new player forum. It’s a pretty expansive list of guilds that are new player friendly.
Short of that, the game now has a vastly improved in game “guild finder” system. I would suggest looking at guilds listed under “social and leveling” and trying out various guilds until you find one that fits what you’re looking for. It’s important to note that unless you choose an RP server, finding other people who are interested in role playing their character’s personal story will be fairly difficult. Unless you plan on just doing that for your own entertainment together.
Finding the right guild can sometimes be a long process, but don’t give up on it and you’ll eventually find a new place to call home.