Depends on how far you want to travel.
For local stuff, it's mostly American River access points and Folsom Lake.
Both have pretty okay biking/walking trails, and obviously you can go for a swim too.
About an hour east you can get to Desolation Wilderness and hike up to some of the lakes south of Tahoe like Aloha, but I don't know how viable those spots are now with the fires up there.
About an hour north and you got Auburn and a few trail heads for nice day hikes. I haven't been there yet, but been recommended them by a couple of my professors.
As for camping and backpacking, I don't really know. I'm really only experienced with day hiking.
Hope this helps.
