Hello, and welcome to Sidosi! We're a pretty small community here, but slowly growing. Here's a quick rundown of the site.
Check out the Resources to find 100+ resources about Solresol. Once you know the basics, read and participate in the forums to examine some of the finer details of Solresol. When you get comfortable with your knowledge, you can start contributing to the wiki, which is intended to be a central resource for information about Solresol. Finally, I coded a translator that can be handy when learning words, though right now it only does basic word-to-word translation, so don't think it's Google Translate!
Don't be discouraged by the apparent lack of activity. Many of our members have school or jobs that keep them busy, so they visit mostly to check for new posts and such. I attempt to keep a work journal to keep everyone informed, but even I'm not the best at logging in enough to post there. In case it wasn't obvious by now, I'm the admin of this site, so feel free to tell me any comments, questions, or concerns about it. I hope you enjoy your stay!