The Salesforce success community is a great way to find information on a variety of subjects, ask and answer questions, and more. This site is definitely worth exploring. Side note: one of the best ways you can learn Salesforce is by answering questions that others have. I learned a ton simply by answering questions on the community site when I first started working with Salesforce.
Salesforce Success Community
Community Should N/A Salesforce.com
A developer edition account is recommended as you can retain control over this account. If you are using a corporate account to access the community site and then change employers, you will likely lose access to your old profile (community posts, Chatter feeds, Trailhead badges, etc.).
Objectives for this Resource:
One of the best part of the Salesforce ecosystem is the community. There are a lot of incredibly helpful people that will go out of their way to help you, and there are great options to get involved both virtually and in person.