Below is a blog from Discourse that explains how new users are not granted all the access to the forum immediately. It also shows how the trust levels are escalated, and permissions are granted.
For those just just want a quick answer, you need to do the following before you get trust level 1:
- Entering at least 5 topics
- Reading at least 30 posts
- Spend a total of 10 minutes reading posts
Among other things, it will unlock these commonly used features:
- Post more than 1 image
- Post more than 3 topics
- Post more than 10 replies
- Send personal messages to other users
For more details for other lifted restrictions and how to gain trust, please visit the link below: