How Can I Be Happier?

[VictoriaLovesSunshineandSea]

I feel like I’m always unhappy lately. I don’t really have many friends, and I don’t have much of a social life or any hobbies outside of work. How do I get out of this rut and start enjoying life again?

By doing all of the above OP!
Start doing hobbies you enjoy, go to clubs, maybe enrol in night classes, meet people who have the same interests as you etc
It all starts there. Things start to get better when you anchor yourself to the world a bit more by putting your effort into things you enjoy.

Good luck!

Maybe I just need to put myself out there more, get involved with the community, and find some joy in meeting people and trying new things?

Take care of your physical and mental health. Do things that bring you joy.
Eat nutritious food
Take some form of exercise regularly
Hydrate well
Get enough sleep
Look for balance in your life work/rest/play
Look for local activities going on that interest you, hobby/interest groups are a great way to meet like minded people
Spend time outdoors - even just a short walk
Clean / tidy / de-clutter your home
If you have a garden spend time taking care of it

Turn your happiness / self care into a project

Nothing to add (I'd agree with all the advice already given) other than to say that what you're feeling, while painful, is very normal, and very solvable.

Can you volunteer somewhere to build contacts, our local parkrun for example is always after volunteers