A lot of (all?) email services will allow you to forward your mail from Gmail. My advice would be set that up, have all of them going to a specific folder, and only use your new email moving forward. No harm in allowing some email forwarding while you adjust for the next 6 to 12 months. But that way you can also immediately stop using Gmail itself.
Gdrive unless it is really baked into your daily life in a complicated way, it’s pretty easy to replace. Lots of great services out there.
Proton mail allowed me to export my Google Calendar over with just a few clicks. So that was pretty painless. I’m sure there are other calendar services like that. YMMV.