As someone who would consider himself a Disney World expert as well and only been to
Disneyland once (and about to go again later this month) I could share some things I learned right away from my first time.
1) I wouldn't say park hopper tickets are a must but they are certainly so much easier to get your monies worth at Disneyland. With both parks being right across from each other you can hop back and forth very quickly. With DCA closing earlier than Disneyland you never have to end your day when DCA closes!
2) As someone who feels like they NEED to stay on property at Disney World I do not feel that same need at Disneyland. The Disney owned resorts are all deluxe priced resorts and don't give you as many benefits as you would get staying on property at Disney World. With how compact things are in the Disneyland area you could stay at much cheaper hotels that are still in walking distance of the parks. Some non-Disney hotels are even a quicker walk to the parks than a Disney owned hotel like the Disneyland Hotel and Paradise Pier Hotel.
3) You definitely don't need to plan as much as you would when going to Disney World. You don't need to worry about fastpasses ahead of time and dining reservations don't seem as hard to come by.
4) We found sooo much worth in buying maxpass. This lets you make fastpasses on your phone through the Disneyland app. A little word of warning...The maxpass/fastpass system at Disneyland is NOT the same as it works at Disney World. Think of the Disneyland system as how the fastpass system works at Disney World once you've used your initial 3 fastpasses for the day. You make one fastpass at a time. There is a "cooldown" period until you can make a new one of either 90 minutes or until you use that fastpass. If it's 9am and you make a fastpass for 4pm, you can't make another fastpass until 10:30am. If it's 9am and you make a fastpass for 9:30am, if you use that fastpass at 9:30 you can make another fastpass right away. I would suggest reading into how the rules work and looking at all the tips on how to use the system and get the most out of it.