making friends after retirement

I know all the normal thngs I should do and I’m doing them. I am volunteering and taking classes for seniors, but after 3 years, there is still no one I can call in an emergency or someone I can have lunch with.. I’m divorced and the former friends are not for me. I was also out of the country for two years.  And, yes, I’m an introvert but friendly…just not good at initiating. any ideas?