My husband and I will be vacationing in carlsbad in April we would like to see the best of L.A., the coast and San diego. We are not that interested in theme parks. How far of a drive to L.A.?

Maybe 1.5-2 hours depending on traffic.

Plan a day trip or overnighter to L.A. on the weekend, the traffic will be much easier to deal with.

The traffic on the weekend is not necessarily easier. You expect it to be, but several times I've come home to San Diego on a Saturday afternoon and been stuck in awful traffic around San Clemente and then from Oceanside south.

What will you be going to see in LA?

you may want to take amtrak to la on the surfliner-

No, you don't want to take the train because then you have no convenient way to get to wherever you want to go. You just have to decide to go and be prepared for heavy traffic. The traffic is frequently smooth-flowing - and fast. When you get just north of San Clemente, the car pool lanes begin. Be sure to use them.

I am also visiting Carlsbad this summer, not until July. If you wouldn't mind, I would love to hear some recommendations of things to do etc., after you get back!
Thanks!