If you own a Pixel, Pixel XL, Pixel 2, Pixel 2 XL, Pixel 3, or Pixel 3 XL, you can jump on this new goodness right now. Of course, being the first preview, it’s probably not stable and you should consider holding off until a more stable beta version shows up in a couple of months, likely at Google I/O.
Unlike previous years, Google has gone beta out of the gate rather than developer preview. That means you can sign-up pretty easily at the Android Beta site, allowing you to grab an over-the-air (OTA) update to Q rather than deal with factory images.
You can download the beta 1 factory images, also the OTA file linked below:
Android Q Beta 1 Release Notes
Date: March 2019API diff: API 28 → Beta1
Build: QPP1.190205.018.b4 (Pixel, Pixel XL, Pixel 2, Pixel 2 XL, Pixel 3, Pixel 3 XL)
Emulator support: x86 (32/64-bit)
Security patch level: March 2019
Google Play services: 12.4.4
Download: Android Beta Program, Android Q Factory Image, Android Q OTA