Also: To sign comments on talk pages, simply type four tildes, like this: ~~~~. This will automatically add your username and the time after your comments. Signing with three tildes ~~~ will just sign your username.
I hope to see you around Wikipedia! If you have any questions, feel free to contact me on my talk page!
Yes you can write a new article. If you click the random page button in the tool bar, you will come a cross small articles or "stubs" as they are called. You can edit these and make them longer or you can click on a red link to start the article. When you click the red link it will take you to a page where you can start the article. If you want you can start an article in the sandbox, or on your userpage, or subpage (example url: User:PremierSullivan/Sandbox).