Cutting and pasting the answer I just sent you in email and adding a little at the end ...
The hub will update itself automatically if you leave it connected to the internet.
To check the firmware version, open hub settings and click on the "i" next to "Hub Name". The important part is the XXX date where it says "release/XXX" in the version.
You can get announcements on any device that's capable of acting as a Google Cast receiver (e.g. Google Home devices, or a chromecast device or Android TV), or you can have it play audio over the headphone jack, but you'll need speakers that can accept a headphone input and amplify it. The jack itself is a combination microphone/headphone jack, like the type of plug used by most headsets today, although we are not doing anything with the microphone input at the moment.
You enable alert announcements by checking "play voice alerts" on the alerts tab of the hub settings.
If you're not getting anything on the headphone output, plug in a pair of regular headphones and try first. If those work, then you need to find an appropriate way of amplifying that output for your speakers, or use speakers that can directly take a headphone output (e.g. there are plenty of computer speakers that can do that).