It looks like this post will miss your trip, but at least let me go on record.
I lived in Long Beach CA for 5 years before moving to Chi town just over a year ago. First, the downtown long beach area is transitional and there are once you get past 5th street (5 or 6 blocks from Ocean) there isn't much to do. Once you get past 8th street, things get pretty dicey and get worse. However, if you are downtown and don't go anywhere you have to eat at Taco Beach (great fish taco's) and George's Greek Deli (Greek salads and really good lamb chops) on Pine Ave. Most other restaurants on Pine come and go and typically don't shine.
ALso, look for a great wine store called Vin de Pay's - everything is under $15 and Tom, the owner, is a great guy and will help you. Most every restaurant in CA allows corkage and has a small fee, even if they sell wine. Don't be shy to take your own bottle (you may want to call ahead, but again, nearly all do)
Find the bus that takes you to Belmont Shore, a beach comunity suburb of Long Beach. Get off on Second Street and walk up and down the quiet little community where I used to live. You are about 3 blocks off of the ocean at this point and the neighboorhood is 100% million dollar homes with a downtown strip. I recommend Sushi-Saurus (Sushi), Taco Surf (similar to Taco Beach), La Crepiere (Crepe's and french food.)
Other great restaurants are further south on Second Street on Naples Island (a man made island with canal's framing million dollar beach mansions between million dollar yachts - you can go on a Gondolier ride here too) which include Kelly's (the classic, old timey steak house) and Sushi of Naples (one of my favorite sushi spots in America) and Morey's wine bar (a wine shop with a tapas restaurant in back really.) North in Belmont Heights (still on Second street) is Osteria Parluccia which is a great Italian joint.
I REALLY recommend you get out from downtown and hit the places in the paragraph above if you can, but again, it looks like this post will miss your trip anyway!
SO, at minimum, let me know if you hit any of the places I recommended, and let this post be a testament to any Chicagoian going to Long Beach CA!
There is no accounting for taste!