Client Side

So, I've heard you're kinda new to web ?

Basically, in every challenge you'll be provided a url and you'll need to hack your way through the website.
First step is usually to look at the source code of the page, so you'll need to know a bit about html/css/javascript. It will be enough for this first challenge, so you can solve it now and come back to read the remaining later ;)

Of course you'll also need some knowledge about languages you won't see the source code, mainly php and various languages related to databases (such as MySQL). After that, you'll have to exploit the vulnerabilities in the web page. For that, you'll need to identify the features provided by the website and do some research on the associated exploits.
Here is some useful links to get you started:
- https://developer.mozilla.org/en-US/docs/Tools
- https://owasp.org/www-project-top-ten/
- https://portswigger.net/burp

Good luck !