Taking my 21 year old to Los Angeles for weekend in Oct. Any good places(bars,restaurants) for seeing the stars? Other bar/restaurant/activity recommendations that daughter and mom might enjoy that might be fun and different?

Definitely depends on where you're staying and whether or not you'll have a car. Los Angeles is vast and huge!

I bet she would love touring the fashion district. Many stores only sell to wholesalers, but some sell direct. I had fun shopping.

http://www.fashiondistrict.org/

It's been a few years but I have great memory of sitting back to back with Geena Davis at James'Beach restaurant in Venice. Venice, Santa Monica, LA's a big place. If beach is important then Venice or Santa Monica should provide lots of options, and some things could even be doable without a car.

Meme
Massachusetts

I was just in LA and had dinner at STK where we sat next to David Spade and Chris Rock... (I was literally shoulder to shoulder with him, a la Lucy at the Brown Derby with William Holden) we also saw a handful of other young famous people that we did not know but everyone else did!
The staff was very nice, the special drinks were awesome and the food was awesome, too.
The later, the better at that place. We ate at 830 and left around 10pm and the place was just getting going.
I'd go back...
You could go to Beverly Hills/West Hollywood/Melrose for the day and have a late dinner at STK, which is just right past the Bev Center... walking distance.
The area is like a new design district or something.
Make reservations and GET THERE EARLY because there is a danger that you will NOT get a table even with a reservation! Have a cocktail and watch people for an hour than have dinner.
Great fun!

The Rooftop Bar at the Standard downtown, and the Edison.

Enjoy L.A.!