Honestly, DCA is a bit easier to navigate, but if you manage your time right, you can avoid 90% of the crowds in both parks.
Additionally, if an area is crowded at
Disneyland, you can always use the train to get to another stop, just remember that Main Street Station is not accessible. But unliked Disney World,
ECVs can go on the train at Disneyland.
Big Thunder Trail is also very wide and great for getting around crowds right now, after Galaxy's Edge opens that will probably change. By small world, there is a path that goes by Storybook Land Canal Boats that is separated from the rest of the street, this can also be a good way to bypass crowds at times.
After the fireworks, they will usually open the bypass on the side of the street with first aid, this will be your quickest oath out of the park, but really if you can stay after the fireworks, crowds will be dramatically reduced.
Another trick is of course be there for rope drop, then if you are staying nearby, go back to the hotel when it starts to get too busy and come back for the night stuff.
One more is get MaxPass for everyone and make full use of it. You can get your first FP the second your ticket is scanned into the parks, even if this is before Park opening. Then you either have to wait until the time it says you can get your next FP it until you have used your FP at the first scanner, then you can get your next FP while in line for that attraction. This dramatically reduced your wait times and increases how quickly you can get on attractions. If you show up in time for rope drop and have MaxPass, you can potentially get through most of the park by 2 or 3 in the afternoon, including attractions without FP.
Overall though, the biggest thing to remember is there are parts of Disneyland that get very dark at night, so the more you can do to remain visible and the better headlights you have, the easier navigation will be for you at night.
Not really related to crowds, but if you want to ride the trolley at DCA, or the Main Street Transportation at Disneyland, they are normally.one way trips, but as long as they are going to return to where you are and not being taken offline, they will usually allow guests in ECVs to do a round trip if you ask nicely.
