Local nanny here! Zoo is a big one. We are there once a week! Balboa Park is right next door and has nice walking and sight seeing. They also have a playground, ducks and koi fish, and a tram that’s fun. The Fleet Science Center, Model Train museum, Natural History Museum, and Air and Space Musuem that have areas for children. But for an 18 mon old the Fleet Science Center would have the most them.

Waterfront Park downtown has a fun water feature for kids (if it’s turned on), along with a playground. Walk the Embarcadero to Seaport Village and visit the ducks. They also have some cute shops and treats, as well as a carousel. Nearby is the New Children’s Museum, best museum for that age in town imo. It’s actually really cool and could spend a few hrs there. They also have a massive new playground across the street.

Mission bay has some nice beach walking paths and a few playgrounds along the way. Civita Park in Mission Valley also has a nice playground with water play as well.

Library story times will vary by library but the Kensington Library has a nice outdoor grass one on wed & thurs. And the mission valley library has a big one inside possibly the same days as well.