First- you will not walk nearly as much. I think of it like this. They built Disneyland, and then expanded everything when they built WDW. The walkways are more narrow. Ride things that are in both parks, Space Mountain, Pirates, etc to see what is different. you will be surprised how different things are.
If they have EMH- it can be as early as 7 am- use that time...
See both parks- you will see some ideas repeated, but also see how it is spread out at WDW.
We have been to WDW considerably more, but we loved Disneyland (my husband liked it better). Oh, and there is fastpass like the old ways- paper... and if you are going to ride Radiator Springs racers- you pretty much have to get there first thing in the morning to get a fastpass... That street (CARS) is amazing... look at the detail on the buildings- it looks just like the movie.
Oh, and not sure where you are staying, but the hotels are nice too- and usually a short walk through downtown Disney to get to the park... its a little different, but it is a nice walk.
Ask away for anything else.... Have a great trip!
