Welcome to the community.
The drupal.org community is comprised of a diverse group of people; from developers to neophytes, professionals to hobbyists, and contributors to non-contributers. Using Drupal as a foundation, you can build a powerful flexible website.
As with all powerful tools, what you get out of it depends on what you put into it. With a base Drupal install, you can build a fairly powerful database driven site without knowing PHP. If you need something beyond what is provided with the base install and the more stable contributed modules, you will need to be familiar with PHP and databases (primarily MySQL), be willing to learn about them, or be ready to pay someone for their services. If you are familiar with developing, then you will want to spend time learning Drupal's API and read through the Developer's Guide. The mail list and archives is also a good source of information for development.
As with all communities, members have many vigorous discussions over various approaches and viewpoints while others work to provide helpful support to friendly newcomers and even the occasional troll. To make the forums a more pleasureable and productive experience for all, be sure to read and keep in mind the forum posting tips.
Open source communities work best when everyone jumps in and helps out. The handbooks mention a number of ways anyone can contribute. Once you have installed and begun configuring your site, you can easily lend a hand by assisting others in the fourms who have the same basic questions you once had. Whether you help in the support forum, write or revise documentation, review patches, or create patches, your help is always welcome.