The topics include social engineering, evading IDS, SQL injection, IoT hacking, cryptography, cloud computing, hacking wireless networks and mobile platforms, hacking web servers, enumeration and etc. There r so many.
For now i just think of reading it and understanding a little on how hackers do it, not planning to do anything with it. I don't know what to do with it.
Hacking was easy back in the day (decades ago), everything was new, no one knew much, it was pretty easy to outsmart "The Man". But now, it is a high risk game. Unless your name is Kevin Mitnick best to just hack your own stuff to learn how to do it and leave it at that. You can run around playing with scripts and stuff and hack easy stuff I guess if you wan't. But if you try a real target, your going to get caught. There is always someone smarter than you, and even when you are on top of that game, the resources that can be gathered to catch a hacker is staggering if you hack the wrong place. My advice, get a spare computer at home, try to protect it, then try to hack it. But keep it safe inside your walls. Hacking is a little like the dark web, if you have to ask how it works, you probably shouldn't be playing there :)
That's my two bobs worth anyway.