Private Messaging
To private message someone on this forum, (or chat as it is called) you first need to raise your reputation. You can raise your reputation by chatting and/or having your posts upvoted. It should not take long for you to unlock the chat feature. Only about 12 messages at this point, though that number can change in the future.
This is requirement is here to keep people from being spammed by bot accounts, and you should only ever have to do this one time. If your not sure where to start chatting, just stop by a general chat and say hi. :)