I know you thinking some wierd,windows are best oprating sytem for many of us, but not for a hacker. If you never used Linux before, consider the CompTIA Linux+ course , it would be a very good start.
Most servers and networks are working in some sort UNIX based OS.
Almost every powerful hacking tools works on Linux.
Step 2: Learn Networking
Networks run the Internet and connect the whole world together. Almost all systems in the world are connected. I recommend starting with CompTIA Network+ for learning fundamentals, they maybe CCNA Routing and Switching.
Another great tool to really understand networking and understand what happens behind the scenes is Wireshark. It will help you to get deep into network!!
Step 3: Learn Security Concepts
You need to learn how security admins work and think and outsmart them. You need to learn about Firewalls and IDS. CompTIA Security+ is a great start. Then you will need to study more advanced certificates like CEH.
Step-4: Learn Programming and Scripting
Because you can’t hack a system without knowing how it works and what are it’s vulnerabilities. Most people recommend learning C or C++ but I suggest you start with Python. Even if you don’t have programming knowledge, you can just search codes over internet and perform the work.
Without scripting skills, the hacker will be relegated to using other hackers’ tools. This limits your effectiveness. Every day a new tool is in existence loses effectiveness as security admins come up with defenses.
These four steps are most important and ofcourse you need to learn SQL and DATABASE but those are not that important. Hacking requires study of hacking books and spending hours on computer. This might make you feel bored and stress but once you start getting results, you will develop interest. Once you develop interest you’ll become a hacker.