quomii
This is broad and probably not the best forum for this. I think you would be better served reading through the features and usage tabs on the website. That can give an idea of what's important.
But a high level overview is; use a strong pin/password, use encryption, monitor device/app permissions, monitor location services, be mindful of WiFi connections, use services / vendors that follow privacy by design, keep OS and apps up to date.
The basis of privacy is consent, so a user should have choice over how their data is used and disclosed. This is tailored depending on a users specific situation, called threat modelling. You can imagine it becomes very easy to write endlessly of the topic.