Apple has released the first public betas of macOS Sequoia 16, iOS 18, iPadOS 18, tvOS 18, and watchOS 11. Public betas are available on Apple’s Beta Software Program website.
Just remember that beta software is unfinished software, so proceed with care. Apple does public betas in order to increase the size of the pool of testers. The tech giant recommends keeping back-ups of your files before installing a public beta.