Sky,
Just a heads up... Traffic from Santa Babs southward to OC is as nuts on Saturdays as the rest of the week. The PCH is usually a parking lot with all the cruising and beach goers.
Your map is too small to read, but it looks like you are on the 101 to the 405 to the 5, if so: There is no car pool lane on 101. From 101 to the 10, 405 does have a car pool lane where it ends until you pass the 105. From there, you have a car pool lane all the way to the 5. By then you should be clear of major traffic until you hit Encinitas where the traffic gets bad again.
Note that the CHP
heavily patrols 5 from the 405 to Encinitas and back. Keep all four eyes open around the intersection of the 74 (Ortega Highway), which is where they seem to be most often. Keep it to 70 mph and you'll be okay.
Also, when going through Ventura on the 101S, CalTrans is rebuilding the bridges over the Santa Clara river. Be real careful as the road jinks severely left then back right. Cagers often straddle the lanes because the kinks catch them off guard. Had a semi overturn yesterday and it blocked the road for a good chunk of the day. The only other construction that you need to be aware of is the section of the 405 that passes the exits for LAX where they are adding car pool lanes. Little tight there, but not too bad.
Then it looks like you're heading back up on the 15... Be aware that there is a check point and be careful of wind conditions - it gets nasty in there!
Have, er, fun!