1) Question- what do you mean your site doesn't show when you search for it. Are you searching "mysite.com"? Set up Google Analytics and Webmaster Tools and submit your site only if you feel it's ready. But since you mentioned you don't know anything about adding keywords, I assume it's not ready yet. So...
2) Read that thread posted. Good advice in there. Start with optimizing your website content and add SEO for Wordpress (Yoast plugin) to customize your meta data. You need to know what your focal keyword is and optimize each page.
3) Yes, building backlinks is important too but then you need to decide if you want to do it white hat or black hat style. Is your site for people? Publish great content and the backlinks should build themselves. Much safer and more effective than paying someone you don't know to spam links that could get you blacklisted.
4) I don't know what your site is about so that's the best I got. If you want to share some more details, I'll try to offer more personalized advice. Best of luck!
