Joyce W.
Yelp
The playground/play structures area are nice, with two levels, one for the littles, and one for older kids. That whole area is gated and pretty safe, although since this is downtown, definitely check before your kids play on the structures and make sure there's no questionable items they may pick up, step on, etc. Overall, I do think people who do illegal activities elsewhere in the large park stay outside of this gated (low gates) area where the kids play as they do respect or know better, and hopefully it stays that way.
The rest of the park is huge, with a pond, a walking/running path, and covers at least 6-8 city blocks, there's plenty of grass, a stage area w/an artistic mural, there's several stone tables for picnics, tennis courts, and even a pool, although at the moment the pool (which is obviously not free and requires admission) is under repair.
Overall, Southside Park is not one of city's best parks, parts of it is kind of rundown, and b/c of its location it's got a lot of interesting individuals loitering after hours or sleeping on the picnic tables, and stone or metal benches throughout the park, and some of whom do things you wouldn't want your kids to see, smell, witness, or try. This is a gathering area for the homeless, with some sleeping or camping out, especially during the pandemic. But it's still a nice park b/c it's downtown where it really needs some urban greenery especially for the neighborhoods immediately surrounding that corner of Sacramento.