You are seeing pictures of the users you follow.

Instagram accounts do not follow people by themselves. I'd suggest you change your password.

Cheers

That's weird you have it showing you followed people but you didn't. Like said above change your password quick. But when you first log in to Instagram your not seeing the pictures of the people your following your seeing the new and improved I forgot if it has an official name but its kind of like a homepage that all users see with trending and popular posts. It's in the second icon also where you search by username and hashtags, etc. But sometimes when you haven't used Instagram for a bit it will open to that page with the popular and trending posts The first icon on the bottom of your Instagram app is your feed where you see posts from people you are following.

That sounds very strange. As above I would either suggest changing your password or starting up a new account (if you're not following anyone and don't have any followers (that you know of) yet)