Dandelion Chocolates is a Willy Wonka Factory-like space that hosts factory tours and classes, as well as educational "chocolate trips" to cacao destinations including Belize and Ecuador.
Start at noon. Get the California Gold sandwich at Mission Cheese. You will die. Did you get that? You'll die.
Next door, you've got two options. Number one. Dandelion Chocolates. I recommend the frozen hot chocolate--it's bomb. Next door to that is Craftsman and Wolves, where they have some pretty good fancy desserts. So that's lunch and a snack.
If you have a car, drive to Bernal Heights, which is...sleepy. Very sleepy. There's a park there, with a hill and a tree. I guess it's called Bernal Heights Park. Almost no one goes there, but it probably has the best view of San Francisco looking northward. Although...if you want to take that picture with the swing that people keep Instagramming, that's Billy Goat Hill.
In the evening, get dinner at Chutney, an Indian restaurant in the Tenderloin. It's my favorite restaurant. Right next to it is a speakeasy, called Bourbon and Branch. Behind a coat rack in Bourbon and Branch is another speakeasy, called Wilson and Wilson Private Detective Agency. When you knock on the door for Bourbon and Branch, it's one password. When you call to reserve, they'll give you a password. But there'd be a different password for Wilson, and you'd also get it when you reserve. Or, you can go to the library. You have to pull a book at Bourbon and Branch for the library. The password is "Books." I don't know. It's always "Books."
Tradition is one block away. It's in the same family of bars, but completely different. I recommend making a reservation. If you reserve, you can go to the back, and you get a book of cocktails with drinks separated by type--tiki bar, dive bar, etc. If you don't have a reservation, you only get a subset of that menu.
Expect incredible city views and very happy off-leash dogs at Bernal Heights Park.
For Fisherman's Wharf, for Lombard Street.
To eat and drink delicious things, and to wear a light jacket everwhere.
The gentrified and non-gentrified parts of the Mission, Chinese food in the Richmond, clubbing in the Castro and in SoMa, Billy Goat Hill, and that gimlet at the Interval at Fort Mason.