I rwcently stumbled upon https://www.hackthebox.eu, a hacker's community with challenges and vulnerable hosts for the members to compete/learn/discuss about cyber security. This seem cool, but I have no freaking idea how to hack my way into the website (please don't spoil me!).

As I'm leaning more and more toward security in my career, I though it would be interesting to learn about these practices and get a bit into it to improve my security skills.

I know about all those "metasploit", "jack the ripper", ... things. But they look like pre-packed stuff you fire once, let run for 2 hours and then you get a reverse shell withou knowing why.

I would like to get my hands dirty, and know what's under the hood. Is anyone here knowledgeable on the topic?
Do you know about resources for complete newbies?

Share your experience!