What should I do if i need keep sensitive notes safe? E-mail services is more trustworthy to do that archiving email to myself, or what? Encrypt the note using which kind of cryptography? More than one e-mail service to make sure I dont lose access to these sensitive notes?
Please, its really urgent.
Use Standard notes or Turtl or Cryptpad
If you need to encrypt regular office documents on your disk, use Veracrypt, PeaZip or Cryptomator
Encrypt it! use AES Encryption App (https://www.aescrypt.com/) or website (https://cryptotools.net/) or use GPG! (see that video: https://invidio.us/watch?v=iEloW5QCvKI and its not the full guide but yeah it works)
PS: do not forget to get a strong password, or generate one and save it
EDIT: no one reminded me, lol
Write them on paper and file in a locked cabinet. All depends on your “threat model.”
I personally use Rednotebook. No cloud