Welcome! Nice to have you with us! New here? Start with following some tags and people! Go check out public stream on your server to find some. Keep adding more people and tags, you can always unfollow something you don't want later.
Also do share your own stuff - write posts, upload images and add relevant tags so similar-minded people can easily find it. Consider filling out your profile as well, no personal data required. Any questions? Don't hesitate to ask, we are here to help.