Unfortunately over the past year or two San Francisco turned 7th street into a "main bike route" which effectively took away all the parking on one side of the street that used to be free.
As Mike said early is better, it is San Francisco and parking is not a guaranteed thing, you may have to do a spiral search pattern if you want to find street parking, or jump into google maps and search for 100 Hooper st. then click "nearby" and enter "parking" in the search window and you should see some pay lots if that's the case. Just make sure not to leave anything of value, or not, visible in your car i.e. a duffle bag or something, not saying the area is crime ridden but that's a really good way to get a window busted into in most bigger cities.
Also of note, if you manage to get to the swap after it started, for whatever reason, we will try to put you a picking group for a letter that is upcoming however you will not get to pick extra for rounds you may have missed.