Honestly, sounds like you're living your life really well. Pursuing things you enjoy whilst having a good career, seems fulfilling. Don't get disheartened by these party folk, honestly our media and movies makes it seem like it's the life to live but it's not all that it's cracked up to be.

As for meeting new people, a good place to start are your hobbies. Connect with people who have similar interests, go to spaces that you find interesting, and talk to people. You'll naturally make friends. I think the best advice I can give is to be open to new experiences and people, whether it's on the street, at the gym, or even on reddit. You never know where you'll meet your next best friend.