Writing software that is secure and ideally secure by design is no easy task. It is well worth taking the time to learn about and understand the issues.
A good example of things to consider is documented at The Dangers of String-Comparing Passwords | Michael's Security Blog and through this you will see that you need to alter the way you think.
There are libraries that help by suggesting "password strength", for example there have been many ports of GitHub - dropbox/zxcvbn: Low-Budget Password Strength Estimation which is arguably one of the original. It is worth highlighting that in 2024 LibreOffice used a C version of this, see LibreOffice 24.2 Community available for all operating systems - The Document Foundation Blog.