Check your email strength
Do you know if your email has ever been compromised? This website created by Global security guru (and proud Aussie :) Troy Hunt can help you see if it has ever been a part of a breach, and it can tell you where and when the breach happened. Dont worry you are not compromising your emails integrity here. Its matching it against a database of known breaches. If you get a result, go to this site or app it mentions and change password immediately. https://haveibeenpwned.com
Creating Strong passphrases not passwords
Passwords are one of the most important aspects of strong security. The average online user bow has over 50 accounts they have signed up to. E.g. Shopping, Banking, Newsletters etc. Approximately 20% of them use the same password for all of them! If one gets breached then it can be used against other targets. Especially high profile ones like Banks. Here's an article on creating strong passwords. N.B You should have a strong unique password for every account you use. https://www.cyber.gov.au/acsc/view-all-content/publications/creating-strong-passphrasesUse a password manager
You need a unique password for every account you have. The easiest way to doo that is with a password manager. They can store them all, create strong ones for you, sync between devices so you have the list on all your devices, autofill in your favourite browser. In other words make life alot easier and making you more secure. After saying that, there is nothing wrong with just writing them down in a pad, but make sure you keep it in a secure place, e.g locked drawer. Imagine if a burglar or friend of a friend visiting got hold of your banking credentials!! This site has rundowns of many. https://www.pcmag.com/picks/the-best-password-managers