You don’t really need to have friends around to make a birthday party. It’s your birthday anyway. You have full control over it.
Do what you like, maybe go out and enjoy yourself at any of the places everyone suggest, or stay at home and enjoy a movie, a book… Do whatever you like the most.
You can buy yourself a birthday gift. Something special, something that you really like or expect people to give you at your birthday.
But most of all, enjoy yourself to the fullest. Think that it’s your birthday party, you are the host and you are also the guest. It isn’t necessary to have people around to enjoy your birthday.
And the last word, happy birthday! Hope you have a great time.