I hardly talk to someone here! Those people on tumblr don’t like me! Hahahah (I love you all, my followers, even though most of you don’t ask anything to me)
You should look for tumblrs that discuss subjects you are into. Most people here like to write or share their love about photograph. You have to look for pages, follow them.. And then, you’re gonna fall into this world, and it’s amazing. On the Search option, type something or the name of a celebrity you like (Jared Leto, for example), and the tags using his name will lead you to fandom pages, etc. Tumblr takes time to get used to, but it’s addicting.
PS: Adding tags in what you’re posting is a great idea to get followers too.