@snugglebug - Aquarium of the Bay near Pier 39? I agree with
@afan - skip it. (It’s kind of sad.) We’re a bit spoiled by the Monterey Bay Aquarium — 2.5 hrs away — but the underwater exhibits at the California Academy of Sciences are pretty spectacular, and much nicer and natural to their ecosystems than what’s at the Aquarium of the Bay. If you’re interested in seeing some marine life, the Cal Academy has a large Phillipines reef exhibit showcasing colorful tropical fish and coral; another tank featuring fish, animals and plants native to the California coast; a flooded rainforest exhibit with Amazonian fish and flora that you can view from under a glass tunnel. There are many other things to see at the Cal Academy, including catching a show in the planetarium, see Claude the albino alligator, checking out the butterflies and plant life in the rainforest exhibit, take in the views of Golden Gate Park and the surrounding neighborhoods from the living roof, etc.
ETA: There is garage parking underneath the Cal Academy, but like many places in SF it is pricey. There is free street parking along MLK Jr Drive and Nancy Pelosi Drive, but a spot can be hard to find on weekends and may have you walking in from far away. I caution you again about car break-ins. Don’t leave anything of value in your car, especially if you’re parking out in the open, even in highly trafficked tourist areas.
The Cal Academy is on a loop that includes the DeYoung Museum right across it, the Music Concourse, and the Japanese Tea Garden (which is a worthwhile stop even with the small entrance fee). A very short drive from the Cal Academy along Nancy Pelosi Drive is the Conservatory of Flowers. Even if you don’t pay to go in, the greenhouse is this amazing example of Victorian architecture that’s worth seeing. Down MLK Jr Drive is Stow Lake, and if you’ve got an hour you could rent a boat and enjoy some time on the water. There are tons of other things to do in Golden Gate Park, especially if it’s a nice day.
I think you mentioned also wanting to check out Amoeba Music? It’s about a 5 minute drive from the Conservatory of Flowers side of the park, near the end of Haight Street. It’s pretty much street parking over there, but there is a Whole Foods with a parking lot right across the street (but you risk being towed if you’re spotted leaving the lot).
He did not dig the vibe
