If you've never been to Disneyland, you're truly missing out because it's a pretty special place. My favorite ever Disneyland trip was one where we got a 5-day park hopper ticket and stayed right across the street at 1 of the hotels on Harbor Blvd, so we could easily walk back & forth every day (closer walk than the Contemporary Resort to MK!).
Going during Gay Days is super fun. But even if you go NOT during Gay Days, nobody at DL is going to give a rip if you're gay, straight, trans, CIS-gendered, pansexual, or any other flavor of the rainbow.
Closest airport to fly into would be the Santa Ana airport...~20 min Uber or taxi ride to hotels right near DL. There's always LAX, of course, Long Beach airport, Ontario airport as well.
DL does NOT have Magical Express (but WDW doesn't either, for that matter). You have to arrange for airport transfers on your own. Stay at a hotel with free breakfast and it can save you some $$ to pay for some extra churros. The Candy Cane Inn is really popular amongst Disneyland-ers on the DL board.