I think some people must have visited a long time ago. We've been twice since 2022, as part of California road trips. We did loads but there are still a couple of things I haven't seen so would go back a third time. We only saw a tiny bit of Golden Gate Park for example. There is loads to see and do. You can even do a trip to Yosemite and stay right in the valley in Curry Village campsite - they have proper tents with beds and electric hook up etc. You woudln't be able to go in February though - snow everywhere.
Stay well away from the Tenderloin and you'll be fine. I'd stick to the hotels in Fisherman's Wharf, the popular ones are on/near Beach Street. Union Square was the nearest we got to the Tenderloin, to go up to the top floor of Macy's to the Cheesecake Factory for dinner. Some of the shops are closing down in Union Square, including Macy's and I think they're trying to think of ways to revive that area.
It's a great city, got lots of character. Very doable on public transport - get the Muni app.It's so easy. Walk a lot, you see much more. Last year when we went we spent a really enjoyable Sunday morning walking around the Presidio, to find LucasFilm offices to see the Yoda fountain 😬. Walked along Crissy Field to the beach to get really good views of the Golden Gate bridge before the fog came down mid morning. There were loads of locals walking their dogs or just out for a stroll, didn't seem to be many tourists except us. We saw a coyote on the edge of the sand dunes. Then we walked to Fort Mason, and got the bus back from there to the Sunset district and had a fantastic Mexican lunch in a little bar in a courtyard before heading over to Golden Gate Park. Only had a time to walk round the Botanical Gardens but would like to see the rest next time.
There's loads to do. But I'm not sure I'd want to visit in February, sorry. It's rainy season. And It's fecking freezing even in summer! That wind - it's biting. And when the fog comes down every day the moisture makes it colder. Be prepared for that. Most people think San Francisco equals California equals shorts and suntan but noooooooo, even in summer it is very mixed. I think it will definitely have a different vibe to summer, too, with fewer people about....
Joint the Facebook group California Dreamers and West Coast Wanderers. VERY helpful group with loads of advice and ideas. You'd probably need to ask about going in low season as nearly everyone goes in summer.