At the top of the page (right here on this page you are reading) is a link "FAQ/Rules" which contains all the Forum Policies.
You are correct that the requirement to customize your appearance here (Avatar and Signature) requires an investment by way of participation.
Sitepoint is dedicated to helping others but also as a place to learn and grow. Browse the forum and find topics that interest you. Then engage in meaningful discussion.
Before you know it, you will have earned the ability to personalize your presence here.
Welcome to the largest meeting place on earth for Web Professionals (and hobbyists)!