In order to learn something, you need to practice it. When it comes to becoming a hacker, that is done by attacking machines in a lab. There are many ways of doing this, such as building your own, spinning up an OWASP or Metasploitable virtual machine, or using a service like Hack The Box. There’s one common flaw with these labs though, they’re not realistic. To build realistic labs that look like live environments is a hard task to accomplish.