If you click on your name, you’ll see that you’ve only made 1 post so far. Only posts made outside of the marketplace count towards your post count. It’s not too hard…you can simply just respond to a pic of a fish and say, “nice fish,” or something like that 5 times to unlock messaging
Certain site features are only available after you have made a specific number of meaningful posts. How long you have been a member is irrelevant to access certain features. PM's are one of those but I do not know how many meaningful responses a person must make