I use both. Proton has the VPN and with Visionary a plan that allows my team to all have email, calendar, and vpn. Tutanota works on GrapheneOS without the need to have Google framework and playservice and still works with push notifications.
Proton allows to interact with PGP users, which is great. Tutanota does not.
Tutanota is cheaper and has a calendar and email working great.
Check also skiff.com as it might be enough for you with the free version. Really depend on what you need.
I remember the time... you got a car, switched on the radio, drove around. Had fun...