Please don't wear leggings with it, OP. Or listen to anyone who suggests you wear leggings with it.
I love the playsuit, it's fun and celebratory and I wouldn't call it tacky whatsoever. If I'm being honest, I don't love the shoes. I think delicate spindly heels can look a bit dated right now, so I'd probably go boots or chunky platform heels with it, but also if the first ones make you happy then go for it.
Ultimately, it's your birthday, wear what makes you feel good and happy and ignore those who want you wrapped in your woollens and hiding out of sight for fear you might (shock!) attact some attention on your birthday.