-Going to Camarillo, as long as you leave downtown *after* the morning rush (9:30-10:30 am), you should be O.K. I'd agree with the previous posters that your radio should be tuned to AM 1070 for traffic reports. Most straightforward route is likely to be US 110 North to the US 101 out to Camarillo.... (be very careful about lane choice while going through freeway interchanges or you can wind up going very much the wrong way on some other highway)

However, if there are traffic tie-ups on the 101 through Hollywood or with the 101-134-170 interchange in North Hollywood (Studio City), you could instead take the 110 South to the 10 West, to Interstate 5 North.....and then joining US 101 North (West) in the middle the San Fernando Valley.

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Coming back is apt to be the trickier problem. Traffic on the 101 between the Camarillo grade and through the San Fernando Valley starts to pick up about 3:30 in the afternoon...and is apt to be a problem till at least 6:30 in the evening. If you plan to be shopping that long and/or grabbing dinner out in the Camarillo area, no worries.

However, if you want to eat in LA, you might take the scenic route and sneak into LA (or at least Santa Monica & the West side of town) via US 1. Simply take Las Posas Road (bordering the outlet mall) South to US 1 and hang a left (East). US 1 follows the coast (mostly in view of the ocean) all the way in to Santa Monica. There are also plenty of great beaches if you'd like to stop and have a look-see. While you can pick up I-10 from Santa Monica to downtown, I would not prior to about 6:30 or 7 pm so as to let all of the evening traffic dissipate. But since there are plenty of restaurants & nightspots over on the westside, take your time.