@eiram After you have read the guidelines (which are mostly about being polite and using correct grammar and not baiting people, and staying on topic if you are in the General section) than just jump on in.
Click on the General section and just read through the questions and see if anything suits your fancy or is up your alley, then click on that question and see what everybody else is saying and then add your two cents. In General, you can certainly have conversations and discussions but your answers need to stay on the topic.
Click on the Social section and see what people are curious about there. Sometimes the questions in Social can be funny or out there or NSFW (not safe for viewing at work, usually due to sexual themes) or they might be questions about needing help (with a relationship problem, a potential medical problem, someone needs to find the right word for a story they are writing, they need advice on how to plan an event, or they need some help finding a recipe that is exactly like what their grandma used to make) and sometimes there are silly, but fun games to participate in (some of which have been ongoing for years).
Sometimes we use silly Fluther Jargon. The words are usually based upon some goofy thread or some really funny Freudian slip that one of the members made. If you want to know what some odd term means, don’t hesitate to ask.
We tend to like to throw virtual parties for members who have reached a milestone with their lurve count (Lurve is what you get when you gain points from other member’s giving your GA’s or great answers, it’s really meaningless, you don’t win any real prizes, but it’s fun for us)
Once you have read a bunch of questions, you’ll get a pretty good feel for the personalities attached to the avatars. I bet you will find that you have lots in common with several folks, if you like what someone had to say, but don’t necessarily want to discuss it on the thread, you can always PM (private message) any one of the members by clicking on their avatar and then clicking the Message button. The default setting of Messages is that they are private, and only the person you are sending the message to will see it. If you unclick the “private” box under the message field, you can make the message visible to anyone who visits so and so’s profile page (kind of like Facebook). I usually keep the private box clicked.
If you see anything that seems wrong or suspicious (potential trolls, very bad behavior, lots of spelling errors) don’t hesitate to “flag” the question or any of the responses within a thread. The flag button for a question is at the top of the page, next to the Q itself. The flag button for any particular comment, is next to the comment itself. Don’t hesitate for flag anything you think is a problem. The Mods (site moderators) are all volunteers, except for @Augustlan (our site manager) and they appreciate the help from all of the members. No one except the Mods (and they are bound by guidelines not to reveal your identity) will see your flag (in other words, if you flag a Q or and A by a member, that member will not know that you flagged it).
If you have any problems at all, use the contact button at the top of the page and the Mods will explain anything you need know (and they’re all a bunch of nice folks too). If you need more clarification, you can always PM @Augustlan directly by going to her profile page and Messaging her. You couldn’t ask for a better set of Moderators and Community Manager than you will find at Fluther.
And welcome to Fluther, now come and stay a spell : )