calendars and contacts

I want to keep these protected, (and outside of big tech).
Something similar to my notes, which I sync between my phone and computer with syncthing.
Is there anything similar for calendars and contacts, that syncs automatically / one click, between two offline encrypted devices.

Or failing that, is there a way I can view my android phone on my computer, so that I can view and edit calendar events on the larger screen, whilst working.
Thanks.

android big big tech calendar click computer contacts devices encrypted events phone privacy screen sync syncthing tech working