@OP you better off to understand and play with demo account of every games, so you can learn by practice. Theory isn't enough to make you understand.
Unfortunately, you can forget about privacy and personal data protection in the twenty-first century. Major brands or websites say that they have the best security protection installed, which will not allow hackers to break into the system. However, people are already aware of several dozen cases of database draining.
Then you should learn how to secure your privacy, you can start by a little thing to not publish your daily routine and hide all of your personal pictures on any social medias. It's hard to achieve fully anonymous privacy, but it doesn't mean impossible.