The national u3a* collects news on u3a activities all over the UK. See here for the latest u3a stories https://www.u3a.org.uk/latest-news (opens in a new tab). It'll be easier to let the national u3a office send you their u3a newsletter. And they don't spam - they usually send one email a month. You can sign up to receive yours here: https://www.u3a.org.uk/news/newsletter (opens in a new tab).
*Our local u3a benefits from the effort, support and guidance of a national u3a umbrella organisation called the Third Age Trust. The initiative above is one of their many projects.