Thank you very much for that. I’ve found it now.
The screen basic view is on page 28 of my version of the manual, I managed to miss it. I’m probably having so much difficulty because it works in such a different way to, for example, non linear video editors. I’m still trying to find a keyboard shortcut to got to zero. The one listed under keyboard commands “.” just makes a beep and 'Shift+B" makes the virtual keyboard flash. In either case the cursor stays exactly where it was.
I’ll keep on it!