Nah, this shit is confusing initially. Think of it like email. You’re using gmail, but you can still see and participate in email threads sent by Outlook users. It’s just that instead of emails, it’s a threaded forum somewhat in the style of reddit.

In case the email analogy doesn’t work for you, let me let me try to explain. You’re on kbin, you can tell because your username ends in @kbin.social, which is a kbin instance. Instance is just another name for a server. Due to federation you can view and comment on threads from any other federated instance. You can also join maganzines (called communities on Lemmy, groups on mastadon, and subreddits on reddit) from any other federated instance as well. The only thing I don’t think you can do is become a moderator on another instance. Note, the content is being brought to your kbin feed because we are federated, if you go to to the original instance you’ve left the website and thus won’t be logged in. There’s nothing to stop you from making another account with a Lemmy instance, but there’s not really any reason to because you can see the same content.

and am not sure if I have the lemmy.

You don’t. You are logged in to a kbin account but, just like if you were logged in to a lemmy account, you can read and post to the same threads and comments. Just like if you were logged in to your gmail account you can send an email to somebody with a hotmail account or another gmail account. Doesn’t matter.