Do not be afraid of making a mistake. Mistakes are allowed as long as you don't repeat them after being made aware of them. Be WP:BOLD but follow WP:BRD if someone undoes your work. Do not worry or hurry about anything except when it's an actual WP:EMERGENCY; there is no deadline, discussions are not live chat, and every single edit you make, including page creations, is saved, and an admin (or a functionary) can find and bring it back for you even if it is deleted.
Be nice to others, especially when you are angry or frustrated; choose your words carefully as people of all ages and cultures edit here and every single edit you make is public. Because everything is public, don't reveal your private information, to protect yourself from creeps and crazies, which include the Law. Visit the WP:TEAHOUSE when you have questions.
There are three core content policies to keep in mind when editing articles: WP:V, WP:NOR and WP:NPOV. Be careful when writing about living or recently deceased people, as you could cause real-world harm; see WP:BLP. Do not copy-paste other people's writings, including from other Wikipedia articles, without understanding about copyright. WP:COPYVIO is taken very very seriously. If you want to create a new article, first make sure the topic is WP:NOTABLE. Bookmark Template:Wikipedia policies and guidelines to browse through other policies and guidelines when you can or need to.