how to stop synching passwords between safari on macbook and iphone?

Hi All

I have a few questions and would be most grateful for any solutions. Thanks in advance !

How do I stop synching passwords & bookmarks between safari on my MacBook Pro and iphone?

I had tried this before but ended up with a whole heap of other issues as I think unticked iCloud un synch somewhere me thinks! Then all my desk top data became confused and I went down another rabbit hole.

I really do not feel safe with my iPhone holding all my website passwords as it synchs to my MacBook where I tend to do all my work online rather than phone... Is there a way to isolate them again and my desktop too yet back up and synch other stuff perhaps.

Im not highly technical so often think I've sussed it but then mess things up somehow...