You can buy tickets right now through a variety of third parties like
UT or others, you just can't make reservations for March yet. You can also buy through Disney and make false reservations for an earlier date than modify them. I'm not really sure why people buy tickets through Disney, as you can easily save at least $30 per person or more by buying through reputable third party vendors. You immediately get an email and link them to the app - easy. I've done this at least a dozen times and never had an issue.
Frankly, I recommend buying tickets in the next month.
Disneyland has been raising ticket prices and LLMP prices annually in late-Sept/Oct. If you buy tickets in September, you'll get the less expensive price for your March trip. If plans change, the tickets don't expire until January 2026 and even then you still get to keep the value of the tickets. Some third parties allow you to get a partial refund.
Other questions you asked:
Rides - there's a list on these boards of unique experiences to DL and similar same as WDW. I'm sure someone will post it.
LAX v. BUR - Honestly, neither of these are great options, but LAX is probably better between the two. If you can fly nonstop to BUR from where you are, I bet there's nonstops to SNA, Long Beach, or ONT. All of those three I would recommend over BUR.
Transport - There is nothing like at WDW. There's a variety of private shuttles available, or ride share. Lansky is one. I have used Anaheim Town Car services. Factor in transport cost when deciding on your airport. LAX is cheaper to fly to, but further away so the transport cost is higher. SNA is sometimes more expensive for flights, but cheaper for transport since it's only 15 minutes away. BUR is very far - it will be expensive to transport to/from there, and the drive down is riddled with traffic.
MagicBand - Disneyland uses ONLY Magicband+. Old Magic Bands will not work there. You can also just use your phone.
LLMP - There is a Disneyland App, different from
MDE. Download it. LLMP is named the same as WDW, but functions entirely different. It's like the old
Genie+ system at WDW, but it actually works. Disneyland and DCA have many more rides in each park than the parks at WDW, and less people use the system, so you can get tons of useage out of LLMP at Disneyland. It is worth getting it. There are 2-3 rides as separate pay options, currently Rise and Radiator Springs Racers. You can't pick a time like at WDW, but they almost always have near immediate return times because not a lot of people pay extra for the separate ride option. Tiana's will likely be included in this once it opens.
I highly encourage you to get park hoppers. It's nothing like WDW. The parks are mere steps apart. Treat it like one big park! You have to choose a starting park, but then you can hop starting at 11:00 am. The parks are also open longer at DL, usually opening at 8:00 am (a huge advantage if coming from the east coast) and during spring break DL will likely close at Midnight and DCA at 10:00 pm. You will have early entry in one park each day since you're staying on site starting at 7:30 am. DCA on Sundays, Mondays, Wednesdays, Fridays. DL on Tuesdays, Thursdays, and Saturdays. Only some rides are open, not everything. In DL it's Fantasyland and Tomorrowland. In DCA it's kind of scattered and all over. Neither of the extra pay LLSP rides are included, Rise or Radiator Springs.