The Mac Observer recommends that you install beta software on extra devices you have lying around. Betas are full of bugs, and you don’t want to install it on your main devices.
iOS 14 Beta for Developers
RIght now the only iOS 14 beta available is the developer beta. It was released on June 22 and the current build is 18A5401v. You’ll need a developer account to download it.
To get started, visit this page and install the beta profile. Restart your device, then head back to that page to download it. You’ll want to read the release notes, which lists known bugs. Here is one such issue:
Updating to iOS & iPadOS 14 beta from previous versions of iOS & iPadOS might take significantly longer than expected. Data loss could occur if the update is interrupted. (59101197)
iOS 14 Beta for Public
Apple always released the public beta once the developer beta has been in the wild for a couple weeks. The iOS 14 beta for non-developers hasn’t been released yet, but Apple said it will be out in July, usually mid- to late-July.
To get started you can visit this page, where you can sign up to be in the beta program if you’re not already part of it. Follow the instructions to archive an iPhone or iPad backup to your Mac. Then tap the button to install the beta profile. Unlike previous versions of iOS, you don’t have to restart your device after installing the profile, so go to Settings > General > Software Update to download the latest beta update.