Sad to see Joselyn's and Aquarius gone...I remember them from my childhood and early teen years many decades ago now (my first new Schwinn Stingray came from Joselyn's in the late 1960s).

+1 for Spokesman in Santa Cruz, great shop, great selection, maybe the best in SC. Bike Trip in SC is very good too, as is Family Cycling Center in Capitola. For used you might try Dave's Recycled in Santa Cruz or a shop on Mission St. with a name that escapes me. Epicenter Bikes in Aptos just opened a second store in Santa Cruz. Owned by a very ambitious young man and they are a Trek dealer. Sprockets on Mission St in SC was always a favorite of mine until Kathy sadly passed away and her husband Phil closed up and moved away--I hear the shop is re-opening with a new owner, but Phil & Kathy were really nice people.

Further afield you might try Cupertino Bike Shop (Cupertino obviously).

For used Craigslist is probably your best bet. Join something like "The Bike Church" in Santa Cruz (hopefully there is a coop like it on the other side of the bay) to learn all about wrenching on bikes.