Most, if not all, US airports have done away with left luggage facilities and lockers - thank the "terrs" for that.

The best advice, IMO, is to take the frequent shuttle (look for the "Hotel Shuttle" stops on the SECOND or departure - not arrivals - floor in the middle of the auto lanes) to the Marriott - it's quite close by, avoids using US 101 (which can get "crowded" at times, and has a large, failry comfy lobby lounge area - plus a snack / bar outlet, bar and restaurant as well.

Or, asuming airline lounge access, have them issue your guest a pass for a meeting with you.

I'd leave any checked baggage checked through to your destination.