You're right that steemit itself is one giant feed. It's not nearly as well organized as many of the other social sites. But people here make pretty big use of Discord for various communities. Some examples are:

• Steemit Ramble
• The Writers Block
• Adsactly

Just to name a few.

In addition, there are a number of contests always going on. Some that I participate in are the fiftywords challenge, and the photo contests by @juliank

I also "first met people" on steemit.chat, so you could start there. Also as you get involved commenting on articles you'll start to see repeat commenters and begin to "get to know" certain people by their comments. People will begin following you and comment on your stuff, and you in turn, will begin commenting on theirs. A relationship begins to form.

Hopefully, this answered your question a bit. Have fun exploring the platform :)