Before I begin - everything about this should be totally and completely ethical at its core. The idea here is information security. I'll say it again. information security. The whole point is to make the world a better place. This isn't for your reckless amusement and shot at recognition with your friends. This is for the betterment of human civilization. Use your knowledge to solve real-world issues.
There are two paths to 'hacking'. I'll try not to use too many technical terms.
The first is the simple, effortless and result-instant path. This involves watching youtube videos with green and black thumbnails with an occasional anonymous mask on top teaching you how to download well-known tools used by thousands daily - or in other words the 'Kali Linux Copy Pastorino Skidder'. You might do something slightly amusing and gain a bit of recognition and self-esteem from your friends. Your hacks will be 'real', but anybody that knows anything would dislike you as they all know all you ever did was use a few premade tools.
The second option, however, is much more intensive, rewarding, and mentally demanding. It is also much more fun if you find the right people to do it with. It involves learning everything from memory interaction with machine code to high-level networking - all while you're trying to break into something. This is where Capture the Flag, or 'CTF' hacking comes into play, where you compete with other individuals/teams with the goal of exploiting a service for a string of text (the flag), which is then submitted for a set amount of points. It is essentially competitive hacking. Through CTF you learn literally everything there is about the digital world, in a rather intense but exciting way. Almost all the creators/finders of major exploits have dabbled in CTF in some way/form, and almost all of them have helped solve real-world issues. However, it does take a lot of work though, as CTF becomes much more difficult as you progress through harder challenges. Some require godlike mathematics to break the encryption, and others require you to think like no one has before. If you are able to do well in a CTF competition, there is no doubt that you should be able to find exploits and create tools for yourself with relative ease. The CTF community is filled with smart people who can't give two shits about elitist mask wearing twitter hackers, instead, they are genuine nerds that love screwing with machines. There's too much to explain so I will post a few links below where you can begin your journey.
Remember - this stuff is not easy if you don't know much, so google everything, question everything, and sooner or later you'll be down the rabbit hole far enough to be enjoying yourself. CTF is real life and online, you will meet people, make new friends, and potentially find your future.
What is CTF? (this channel is gold, use it) - https://www.youtube.com/watch?v=8ev9ZX9J45A
CTF compact guide - https://ctf101.org/
Upcoming CTF events online/irl, live team scores - https://ctftime.org/
What is CTF? - https://ctftime.org/ctf-wtf/
> Be careful of the tool-oriented offensives oscp ctf's, they teach you hardly anything compared to these ones and almost always require the use of Metasploit or some other program that does all the work for you.
- http://pwnable.tw/ (a newer set of high-quality pawnable challenges)
- http://pwnable.kr/ (one of the more popular recent wargaming sets of challenges)
- https://picoctf.com/ (Designed for high school students while the event is usually new every year, it's left online and has a great difficult progression)
- https://microcorruption.com/login (one of the best interfaces, a good difficulty curve, and an introduction to low-level reverse engineering, specifically on an MSP430)
- http://ctflearn.com/ (a new CTF-based learning platform with user-contributed challenges)
- https://maxkersten.nl/binary-analysis-course/ (suggested by /u/ThisIsLibra, a practical binary analysis course)
http://picoctf.com is very good if you are just touching the water.
- A Reddit user /r/slicklibro