I think 5 days in the park is perfect, especially if you want to take breaks during the middle of the day, or if there are days you want to sleep in.
This is cheesy and nerdy, but also takes less than five minutes, so it's worth considering. Stand in the hub in
Disneyland near the partners statue. Look around and see the paths leading to the different lands. Remember this what Walt Disney imagined and not only lived to see come to life, but is still with us today. This is the park that Walk Disney not only created but also walked around in.
CarsLand is one of the absolute best things in Disneyland. It is a retro neon delight after it gets dark. It looks amazing during the daytime too. If you can manage to ride RSR racers during the daytime and the nighttime do it. The ride is amazing any time of day, but it is a different experience based on when you ride it.
Pirates is not a carbon copy clone, so that is absolutely worth riding.
I would say start in DL for the nostalgia and the feeling of seeing what Walt envisioned and supervised the creation of.
If you are into guidebooks, this one is fantastic.
https://www.amazon.com/Unofficial-Guide-Disneyland-2023-Guides/dp/1628091339/ref=sr_1_1?crid=Z0F6YOWEZ969&keywords=The+Unofficial+Guide+to+Disneyland+2023&qid=1670527617&s=books&sprefix=the+unofficial+guide+to+disneyland+2023,stripbooks,77&sr=1-1