What are some good resource's/methods to make and keep long term friends?

I haven't had many real friends.

I had 4friends in primary school 1 and a girlfriend in highschool. I have 3 coworkers I consider friends but only 2 of them I have hung out with outside work but they have a lot closer friendships. I had 40+year old friends but have drifted now and they don't talk to me. I met them from a hobby but there's no one my age.

I had a abusive childhood then was realy sick in my teens and got my job at 19 and never went to uni, just got my license these problems have made it a lot harder in every aspect of life.

I have always admired older people who have had the same friends for 20years.

What are some good resource's/methods to make and keep long term friends?
Post Opinion