Hi neighbor, congratulations on the new ride! (I live in Lafayette.)
Sounds like a fun trip you have planned...should be fairly easy because all the places you're going are fairly close to Superchargers and you're traveling in a fairly Supercharger-rich environment. I've taken my S85D between Lafayette and the Monterey area a bunch of times (most recently for TMC Connect last month), as well as 101 home from SoCal.
@SMAlset gives good advice. The Gilroy Supercharger is a good first charging stop. You didn't say whether you had destination charging available in Cambria for your few days there. If not, you could stop at the Atascadero Supercharger on your way (sort of) to Cambria to pick up some electrons for your local driving there. Going to Marina, you'd probably stop at the Seaside Supercharger (again assuming you need a charge to get there or if you need energy for your local driving around the Monterey area).
I echo the suggestion for 17 Mile Drive...there have been many gorgeous photos of Teslas taken there. Expect your car to draw some attention from tourists, and possible Tesla time.
Coming back up to Walnut Creek, you could use either Seaside or Gilroy to get enough energy for your trip back. There are Superchargers in Dublin or Fremont if you need them (you probably won't), although in general I avoid the Bay Area superchargers except in emergencies because they're frequently congested.
A lot has been written in other threads about doing road trips in a Tesla, which I won't try to repeat here. But here are a few tips for your first road trip:
1) Remember that driving an EV on a road trip is somewhat different from an ICE car. You don't fill up your "tank" at a Supercharger, just charge enough to get to your next stop (plus a margin). Your car charges faster on the "bottom" half of the battery, so if you try to get a 100% charge at a Supercharger you'll be sitting around for a really long time. If you have destination charging at your overnight stops, use those to give yourself a full (or nearly-full) battery to start your driving for the day.
2) While driving, put your next charging stop (or destination) into the Nav, and then put the trip energy graph on the CID, so you can watch your energy consumption as you progress towards your destination.
3) If you're picky about cleaning your windshield, bring cleaning supplies with you (glass cleaner, etc.) because you won't be stopping at gas stations.
Hope you have a safe and fun trip!
Bruce.