I am going to Irvine for business in August and I'm from the east coast. What's the closest nice beach where I can sit and relax and enjoy myself, not just the view but the total beach experience (e.g. nice for walking, etc.) Thanks!

Definitely head to either Laguna Beach or Newport Beach (Balboa Penninsula). Laguna is great at night actually, and Newport is great either night or day. I prefer Balboa, used to live on the Penninsula a few years ago before I settled down and it is just great! Have a great time!

My vote would be for Laguna Beach which I think is the ultimate So. Cal. beach city. Newport is nice, but for the tourist, Laguna is tops.

I will be staying in Newport beach for 2 days in late August. How far away in terms of driving from Newport to Laguna Beach? Is it safe to go to Laguna beach at night? Any must do in Laguna beach?

Balboa Beach is my favorite beach area. The cruise around the area is fun.

There are also some less crowded beaches on PCH between Newport and Laguna.
Pelican Point and Crystal Cove are state beaches.Five bucks to park on the bluff and walk down to the beach.
You'll have much more sand to yourself and you can walk long distances. Some places are open and sandy and others are rocky with tide pools to explore.

Yes, Garrett, it is VERY safe in Laguna, unlike some beach towns where it can get crappy looking when you drive INLAND. Not so in Laguna!