Hey there Katrina,
Thanks for stopping by planDisney with your question - these are great questions!
I'll start off by saying that this is very much subjective here, but happy to give my take and suggestions for you to weigh as you continue to plan your trip.
For me, I almost always start the first day of our family trips by visiting the Disneyland Resort. There's just not much like walking down
Main Street, U.S.A. to really sink into your mind that you're officially on vacation at the Happiest Place on Earth.
When I visit with my family, we typically visit for 2-3 days and we also often purchase the
Park Hopper option and
Lightning Lane Multi-Pass for some added flexibility in our plans. Due to this, as I mentioned, we'll usually set our
park reservation for our first day for Disneyland Park and therefore will switch it up for Day 2 to begin in Disney California Adventure Park.
Since we can swap between the two parks starting at 11:00 AM with the Park Hopper, this lets us flow between the parks based on how the crowds are and what we want to do or see next. However, to your point, we also like to spend at least one night in each of the parks. In my opinion, nighttime in the parks is the absolute best - I tend to enjoy it even more than the day time.
We're just coming out of the season of life where we have to take midday nap breaks with our kiddos, so having the Park Hopper option made it even easier for us to start our morning off in one park, eat lunch, head back for a nap then switch up the scenery for the evening in the other park.
One last note - make sure to catch the brand new show at Fantasyland Theatre, "
Bluey's Best Day Ever!" This kicks off in just a few days and will be so much fun, especially for little ones.
I hope that helps, Katrina! Thanks again for your questions and make sure to come back and see us if you think of any follow ups.
Have a Magical Day,
Greg