If you want to test the full features with a controller that isn't "Hardware Unlocked," you can start a free trial.

This allows you to mix two tracks, use cues, loops, and effects directly from your keyboard and mouse. 2. Hardware Unlocking

You can use Serato DJ Pro indefinitely for free without a license if you are only DJing with your laptop (no external controller connected).

Open Serato DJ Pro and click the "Free Trial" button in the software interface.