There’s no value in worrying what people might think about you. I don’t mean to go out looking weird or to be in appropriate, but just use your own compass to work out what you want to do/say/look like/be.
Turns out, when you get to about 50, you learn that most people are worrying what other people are thinking of them, and not thinking of you at all.
You can be true to yourself and do what you think is right for you, wear what you think is appropriate for the situation, and this attitude applies to everything.
Another – Life’s short. Most people from your past are happy to be friendly and caring. People from school, for example, they are over any groups or cliques or differences you might have been aware of back then, and you should be too. Mostly people just like to connect and look out for each other a little.
Finally – Keep making friends. Keep reaching out. If you are healthy, you’ll find you start outliving a lot of your friends. I’ve seen older people who have lost their best friends and other friends haven’t come along to fill the gaps.