Welcome to SR, Bjo! It's good to have you with us. That can be a challenge! I'm in my forties so birthdays aren't a big deal to me- I like to avoid mine! I really like going to the movies and actually would rather go alone than with someone. I'm not the kind to chat through a film, I'd rather not be distracted. If you don't care for that I guess it's out, but there must be something you like to do. Sounds like reading, watching a film at home or maybe playing a video game would be decent ideas.
Hopefully someone will have better ideas than I do! Congrats on starting down the road to sobriety. It can be tough especially in the beginning but life gets better and better once you ditch the booze.