You download Tableau Server for trial. You install it by clicking next next next and enable the 14-days trial license.
How many users you can create inside tableau server with trial license ?

Answer: 10 users.

Tableau server administrator can check it out from inside Tableau Server -> Settings -> Licenses:

Or using tsm command from terminal:

So you can create 10 users for testing tableau server permissions. Give 10 people access to Tableau Server so they can publish visualization and use other cool features such as: alerting, subscription, download, embedding, web editor, and many others.

Enjoy your 14 days trial.

Data everywhere. Tableau for Everyone 🙂