Generating new Passwords
Use dicewire (Diceware site) for new passwords combination.
For really random passwords use pwgen (pwgen site). It is also available in linux by sudo apt install pwgen or sudo pacman -S pwgen.
Storing Passwords
It is possible to memorize strong and long passwords, check it out with this xkcd.
Checkout also pass(pass site) for storing passwords security in your personal computers using gpg to cryptography those.
Public Storage
When using public storage as protonpass or Bitwarden (a private company that can lose your passwords), always add a new word after the password stored.
For example, if in a new site www.example.com the bitwarden generated CageBobbleQuartersRoutingRebalance password, add a unique word that only you know, like, vidiots and do not save it on bitwarden.
bitwarden will CageBobbleQuartersRoutingRebalance but the real password is CageBobbleQuartersRoutingRebalanceVidiots. You will repeat it for all passwords.