You can download and run Android Q on all Google Pixel devices, to get Android Q on your Google Pixel device, you need to be a part of the Google Android Beta program.
How to Download Android Q:
Once you are a part of Google's Beta program, you will receive the build over the air. Android Beta program users can enroll Google Pixel devices from the source link below.
What's new in Android Q:
Privacy: Google introduced new privacy and security policy with Android Q to enhance privacy for OS controls, file based encryption, Google Play Protect, and more. With Android, Q Google has also provided options to control an apps' access to photos, videos or audio collections via new runtime permissions feature. Also, apps that access downloaded files on your device have to now go through the system file picker. Android Q has a unique real time running feature which will prevent any background app from launching an activity unless it is essential, such as alarms or an incoming call.
Control over location: Android Q will give you more control over the location sharing. With Android Q, the user will have the option to provide app permission to use location all the time, only when the app is in use, or never. This is an extraordinary feature I found which will help your phone to save better and internet data.
Device location access and foldable screen support : With new folding smartphones support one can let two apps work simultaneously, and to notify the app when it has focus. Apart from that, Google will also give you to decide how your app is shown on foldable screens. We should hear more on that in the upcoming betas.
Sharing shortcuts: Android Q with a new shortcut feature in Android Q user can jump directly into another app for sharing content using a feature called Sharing Shortcuts. Also, the next Android version will include a new settings panel which will let you see key system settings such as Wi-Fi connection, network, and aeroplane mode on third party apps via a floating window.
Dynamic Depth Image: With new Android Q image feature, apps can request a 'dynamic Depth Image' which allows you to use specialized blurs and bokeh options as well as enjoy 3D images and support for AR photography.
Source: Android Beta Program