meetups, conventions, conferences, concerts, bars, hobbies, etc. It might be easier for me because I live in a very populous region, but I’ve found it pretty easy to meet people. 90%+ of those people don’t end up becoming long term friends, but that’s just how it is.

Also, the easiest way to start a conversation is to ask a question. “Hey what’s that?” “What are you doing?” It takes time to get a good feel for whether or not someone is actually looking for a conversation based on their response, but it is a skill anyone can learn and there’s generally no harm in short chats with strangers in public spaces.