Birthday dinner with the girls in Costa Mesa Area
I'd second Anqi for a girls night out. The vibe there is lounge-ish and a little smoother on the service than CP. It's the perfect place to head out for some fun dressed to the nines.
If you're looking for something with less giltter but great food, the Crow Bar in Corona del Mar is good (veg options may be limited) and I hear it gets a pretty crazy crowd there late on Thurs nights.
There are a couple of fun options at the Camp: Taco Asylum, Old Vine, and as a plus, you can always head over to Mesa to continue the night.
Though I think the food is overpriced (but good), Sol Cocina has a good vibe and a pretty layout.
Since you don't seem above dining at SCP, you could also try Charlie Palmer at Bloomingdales.
Vegetarian options are going to be limited, but I have always had fun doing yakatori with a group, and Shin Sen Gumi is a lot of fun (it is next to the Ramen place that is listed here).
Shin Sen Gumi Hakata Ramen
18315 Brookhurst St, Fountain Valley, CA 92708
Old Vine Cafe
2937 Bristol St # A102, Costa Mesa, CA
Charlie Palmer At Bloomingdale
3333 Bristol Street, Costa Mesa, CA 92626
251 East Coast Highway, Newport Beach, CA 92663
2937 Bristol St, Costa Mesa, CA 92626