1

Do what is fun for you. Your child will be happy just to be with you having fun together.
Can't beat spending $5 on some sand toys at a CVS and just hanging at the beach.

http://www.visitnewportbeach.com/things-to-do/activities-and-attractions/

2

Will you have a car? Legoland is an hour's drive south. Take the Balboa Island ferry. Taco Rosa and unless there's been a crack down fabulous food trucks line up every Thursday at the Orange County Fair grounds from 11am to 2pm near the Farmer's Market. Fair Drive in Costa Mesa. About a 20 minute drive. Try to find John Wayne's house like I did over 40 years ago. 2686 Bayshore drive. Big man. Wasn't wearing his toupee! Who knew??! OMG just Googled it and can readily see some yokel tore down the unassuming house and built a pretentious behemoth in it's place. in fact looks like all the smaller ranch style homes that were in that area have all been torn down and replaced with too big for their lot homes. Sad but a way of life in SoCal. "See me? See my big house?" Sign of the times.

3

Ask about minimum age before you book a whale watching tour, unless you have a baby sitter lined up. I don't think a 20-month old will be allowed on board.

I see from your other posts that it will be September. So far, this has been a good year for blue whale sightings in California. One Newport outfitter reported seeing 19 of them yesterday. Good chance they will still be around next month.