Bahia Honda is great, but they had not reopened much of the ocean side when I was there this past May. It took a beating from Irma, so you might want to Google it and see what has and has not reopened. Of course the Gulf side is beautiful and calm. And you can sit at water’s edge. It can also be super windy, so watch your stuff.
if you end up just walking around, be sure to visit the Butterfly Conservatory. One of the beautiful inhabitants just might land on one of your shoulders or fingers. It is at the Southern end of Duval St (the opposite end of Mallory Square). And along the way there is a great ice cream place on the opposite side of the street from the Butterfly Conservatory. Flamingo Crossing - perhaps a bit more than 1/2 way down.
And your toddler just might love the chickens & roosters. Especially if there are any baby chicks around. They are everywhere. Some even march down the middle of the street.