This article from Wolters Kluwer provides a good primer on some of the issues that trusts face under the new Corporate Transparency Act.
Trusts, if they are created from a state filing, can be reporting entities under the CTA. They also can be beneficial owners of entities with reporting obligations.
If a trust is either a reporting entity or a beneficial owner, then you need to determine who is the person or people who are the trust's beneficial owners.