I don't know any other ENTPs but I can definitely tell you where I can be found: At social gatherings. Be it a birthday party, pool hall, a bar, barbeque, or church. If there is a lot of people then I will want to be there. I also like to spend time at bookstores. However that's when I'm alone and in my anti-social mood and just want to be lost in a book.
At a social gathering I will be laid back and even reserved at the beginning. It's usually because I'm observing the situation and seeing who's who. I make some connections in my head and decide who to speak with first. Then I talk to someone else, then someone else. -----Look out for that. It's a major clue.
During conversations I like to joke around a bit and make people laugh. I also try to hook people into a subject and suck them into something I'm passionate about. It's how I become the center of attention. I'll have a group of 4-6 hypnotized by some mesmerizing story I've got to say.
During the conversations I talk about a wide area of things. This is the neon sign above my head that says ENTP. I will be knowledgeable in multiple subjects. I can literally talk about anything. If you have a computer issue. I'll tell you what it is. Does you're knee hurt? Here's how to fix it. Legal issues? I'll explain the law to you. Want to go camping? I'm the guy to go to. Want to learn how to ride a motorcycle? I can show you. Politics? studied that too.
Of course, since you are an INFJ, you should be able to talk for hours on just about anything. Usually. I know 3 INFJs and I've spent hours upon hours talking to 2 out of the three.
When you do meet an ENTP, and you will, remember to let em breath in a social situation. I've had INFJs suck up all my attention and follow me everywhere and I would feel suffocated because I didn't get to talk to anyone else the entire night. When it's just the two of you then have at it and have fun.