Hi, I'd like to help you with your question.
It is very common for people to feel like they don't fit in. It's easy to feel like an outsider and what you say is boring to others. But it is not.
People all react differently to the world. Some will do anything to fit in, some don't care (or pretend not to) and others are in between. People respond according to their own issues. Since most people are insecure and want others to like them, they will gravitate to those who seem to have a lot of confidence, whether or not that confidence is authentic. That is probably what you are seeing when you notice other people "fitting in".
When you talk with others, keep in mind a few topics you find interesting. Read the paper or watch the news. What stories stand out to you? Gather as much information as you can about the story and share it with others by saying, "Did you hear about.....?".
Also, what about yourself is unique? Do you have a hobby you love? Any good books you've read? These are good "deeper" topics, when you get through that first 5 minutes of superficial information and are looking for something deeper to talk about.
People love to talk about themselves so ask questions of the other person. What do you find appealing about them? For example, if you like someone's hair style, ask where they get it done. Ask about favorite places to take a vacation. Whatever you feel you might find interesting about them you'd like to know more about. As they talk, add a few thoughts of your own. Make eye contact intermittently, so they feel you are listening. People like to be heard and it often makes them feel closer to you. Be careful not to bombard them with questions, but a few good ones will help the conversation move along.
Pay attention to the good things people have said about you. A good sense of humor is rare so work on your skill. Try to mention something funny in each conversation you have. Don't push it, but if you do find something amusing, mention it.
If you feel comfortable enough, invite a few casual friends out for a dinner. Try to make it at least two people. One on one is hard because there is only two people holding up a conversation. But when you add another person, then you will have time to listen to how they talk to each other and learn. You also have time to practice your skills.
Here are some books to help you:
Making Friends: 8 Steps to making friends quickly and easily: How to make friends and be comfortable with yourself by Steven Aitchison
How to Instantly Connect with Anyone: 96 All-New Little Tricks for Big Success in Relationships by Leil Lowndes
How To Win Friends and Influence People by Dale Carnegie
You can find these books on Amazon.com or try your local library for copies.
I hope this has helped you,Kate