Hi there Michele,
On my website there is a screenshot on the front page, and I will slowly be adding more, let me know if you want a different one.
I have modified the live-config hook to enable auto-login on TDM, this means that you should never need credentials. However, bugs happen (not that I have seen though) and if a user needs credentials for the live environment, they remain the standard live/user, same as Debian.
I will also have a new updated live ISO out on the 27th to include the latest Trinity updates (new xdg-desktop-portal and ebook reader included). The ISO will be updated for every new Debian and Trinity Release, and upgrade scripts are eventually coming for when Trixie is stable.