There are a number of marinas in Redwood City AFAIK
which offer guest slips; there are also overnight anchorages allowed (as I recall). You can stay in Redwood City, or a few miles up the bay there is also Coyote Point marina - probably a day's sail from Redwood City in a smaller boat, as you'll be beating against the wind to get under San Mateo bridge.
If you are ambitious, the North bay has a number of marinas near San Francisco - around 20 miles from Redwood City. Again, in a smaller boat things take a little longer, but a nice trip could be from Redwood City to Coyote Point, then to South Beach (for example), and then it is normally a nice run back to Redwood City.
Two final observations; First, check the tide tables; you can easily have 2-3 knots of current, and if your boat is averaging 4 knots and you want to got 10 miles against the current....well, you get the picture.
Also, on a regular summer day afternoon winds are ~25+ knots. Just want to make sure you are comfortable with that, because if the tide is ebbing, and the wind is coming in at 25knots, a short, 4'+ chop is typical. You may get wet.
Have fun! It's a great place to sail.