If you're interested in baseball there are a several teams in Northern California. Of course the Giants and A's are the most obvious, but there's also minor league. The Sacramento River Cats (Giants) and the Fresno Grizzlies (Astros) are AAA. There are several A-ball teams like the San Jose Giants, Modesto Nuts (Mariners), and Stockton Ports (A's).
I mention the North Coast because I've frankly never been there other than maybe the upper part of Sonoma County. I've lived in California nearly all my life but haven't been up there. And these days it's somewhat known for marijuana tourism, but also for the biggest redwoods. There are redwoods further south that are still spectacular, but not quite the same. I also watch a bit of local cable TV, and for some reason I see a lot of San Diego and Humboldt County tourism ads. They don't have them online, but there's this Alice in Wonderland style ad campaign for Humboldt. This isn't the ads I see most of the time, but it's part of the series.
If you don't have the time or inclination to go up that way, there are redwoods along the central coast.