San Francisco is an absolute pleasant city. A food lover's paradise. A cyclist's dream. A baseball enthusiast's heaven. It has delightful weather with little pockets of microclimates scattered about.
I've been fortunate enough to go twice in a year. Once on a California road trip to see baseball stadiums and the other time for a wedding. I'll lump everything we did on both trips into one list. We flew into San Francisco, rented a car from the airport, and stayed at an Airbnb both times. The first time we stayed for 5 nights and about 4 1/2ish days. The second time we stayed for 2 nights and 2 days. I thought that was plenty of time to really see and do a lot. I hope you get a chance to go here one day!