I'm not sure how to answer to a previous answer so I joined the chat and I couldn't ask anyone as I'm lacking repuatation.
Come on guys, this side is supposed to be "easy" and enable an instant interaction -isn't it?
This site's number one focus is providing Quality Answers and Questions. The reputation is modeled around that - for both Chat and on the site. Gaining 20 reputation is relatively easy so long as you participate within the site (If you gain two up votes on either a question you have authored or an answer - as an example). The Chat is considered a Third Place on the StackExchange network and isn't the main focus of the site as a whole.
I believe it's meant to deter new users from jumping into chat and asking questions without first understanding or participating on the main site.
It probably prevents people from being able to spam the site with bots because you actually have to do something non trivial on here before you get the rep
I don't know why, but getting that reputation is pretty easy. Just explore the site a little bit, vote on some questions and answers you like or register on other Stack Exchange sites and you will get them.
Would you have used the site enough for feedback before getting a meager 20 rep?