How can I know if I am hacked?

Could you please explain to me, in detail, how can I possibly detect if my account has been hacked? I'm quite concerned about my online security and I want to ensure that my personal information and digital assets are safe. Are there any specific signs or symptoms that I should be looking out for? Would regular software updates and strong passwords be sufficient to prevent hacking attempts? Or are there additional measures I should take to enhance my online security? I'm eager to learn more about this as I value my privacy and financial security greatly.