Commuting SJ to SF Cal Train on a foldable bike?

I live in San Jose, but am considering working in San Francisco, which I have done in the past but the bus/MUNI connections to Cal Train made it extremely long.

SO, I'm thinking about getting a foldable bike, and I'd like to know...

1) Can I ride my bike from the 4th & King's Cal Train station to the de Young Museum in Golden Gate Park?

2) Can I walk or bike ride to creative agencies near Mariposa, if I exit on the Embarcadero Cal Train stop?

Please advise.

Thanks!

If so, how long will it take, and is there a safest route in the am & pm?

Also...

1. The CalTrain ride will be 60-90 minutes depending on which train, a lot of trains are express.

   De Young is roughly at 9th and Lincoln. Hit Yahoo! Maps and check out the route. There is a big hill in the way, but you can go around it via Noe/Duboce then zigzagging to the Panhandle. It’s also a straight shot on the N-Judah from CalTrain to 9th and Irving, just a few blocks away — and you can take a folding bicycle on the N-Judah. The N also stops at Noe/Duboce if you want to take it just through the mountain. Figure 45 minutes either biking or transit, not counting the Caltrain ride. The N runs underground so it’s fast. Usually.

   There is no Embarcadero Caltrain. If you want Mariposa, you could try 22nd street or 4th/King. 22nd is closer, but a lot of trains from San Jose don’t stop there. Figure 10-20 minutes of bike.

2. You can ride your bike wherever you want. All roads in California, except freeways, are legal for bikes.

   I suggest you first scope out the route on foot and see what it’s like, and then try riding your bike one day when you aren’t in a rush and see how it goes.