Advice needed 😭

So how do people make friends. Like best ones. I'm not really sure what else to do and it's really difficult. Here's some background.

1. I had friends in primary school, a particular best friend. We all went to different schools as teenagers, we didn't keep in touch.

2. I had a close group of friends as a teenager. We all went to study and made new circles.

3. As an adult I cut alot of friends because of they way they were treating me and I don't want toxic people in my life.

4. I've now started to build friendships with new people but I'm struggling. They all have best friends or a close group. Any friends I do have our couples friends. I've tried reaching out to old friends and no one has responded. It's rubbish.