First ride this summer using navigation, got constant alerts for next point, how do I turn this off,
Your descriptions are unclear, can you post a screenshot / Picture of these "time to next point" notifications. If you have disabled course points (for the course(s) you are loading) then it sounds to me that you still have "Turn Guidance" enabled [Menu > Navigation > Courses > Course Options > Turn Guidance (Enabled / Disable)]
If its been a while since your last ride then perhaps the VeloGPS 830 Navigation & Data Screen Setup Videos might jog you recall? https://www.youtube.com/playlist?list=PLwZvUUCaBp9BW_Dl2c0QJi8iSrn80r3FZ