>since it would be short, I have put together calendar and notes

I've never been someone who uses the calendar a lot so the change has been quite easy for me, but anyway, having a Proton account I can use their calendar also through ProtonCalendar (https://calendar.proton.me/) and it's the application I've been using currently and I don't have many problems with it, for some reason I don't get notifications as they should, but well just open it and the notifications come in, proton calendar is a complete calendar that allows you to sync through your proton account and have the calendar on all devices and it's enough to have a proton account to use all its services. So far I haven't missed any calendar service I've used before.
As for notes I have been using Simplenotes (https://simplenote.com/) which I use to store not very important data and it helps a lot to have it synchronized between all my devices, simplenotes is available for many platforms and this is excellent allowing you to have all your notes on all your devices synchronized in real time. To save more important notes I use Bitwarden's secure notes (https://bitwarden.com/) feature so not only do I not need to use any other notes app, but all my notes are secure and kept private and in sync across all my devices. In the old days I used to save my notes locally on my pc, but I have started using these services so I don't have 30 copies of my apps so I don't lose them all over my devices.

Anyway my experience using these services has been excellent, they are very complete apps and there is no need to use closed and not very private apps like google apps to save things as private and important as notes and calendar.