If you are the plaintiff (landlord) and the tenant/defendant you are suing has filed a response with the court, you need to file a Request/Counter Request to Set Case for Trial - Unlawful Detainer (UD-150) to have the court set your case for trial.
Note: Before you can proceed to trial, all tenants/defendants must respond to the service of process. If any of them fail to do so, you may need to have a default entered.
If any of the tenants/defendants should be dismissed from the case, you may need to complete and file a Request for Dismissal (CIV-110).
If you are the defendant (tenant being sued) and you have filed a response to the lawsuit, you may also file a Request/Counter Request to Set Case for Trial - Unlawful Detainer (UD-150) to have the court set your case for trial.