YAYAYA for Disneyland! I took my first (and solo) trip there in March, and honestly knew NOTHING about it, so I'll try to help ya through as much as I can.
#1: Dining. They don't do ADR's at DLR, you just walk up to the resturant, and make it right then and there. For character dining, there's Princess lunch at Ariel's Grotto in DCA, I seriously suggest it. I'd say go to the resturant the day before, or the morning of, and make the reservation (I also strongly recommend the santa maria tri tip. Greatest meat I've ever had)
-In DCA, for Counterservice: Cocina Cucamonga Mexican Grill is another one of my faves, they've got delicious food, and big portions, but it's not a heavy meal on a hot day.
-Over in DLR: I wanted to try the Big Thunder Ranch BBQ, but being by myself figured it wouldn't be worth the money, but I'd try it out!
-For a quick breakfast: Jolly Holiday Bakery Cafe has great and delicious options (it's right down Main St, where you would expect Caseys to be)
-Across from it, is the Plaza, which has Minnie & friends character breakfast, but then converts to a quick service place for lunch & dinner, (if you want red velvet cake, this is where you'll find it)
-In New Orlean's Square, I GREATLY recomment Cafe Orleans for a dinner (TS) it has amazing and great good, and really good pricing, again, you can just walk up and ask for a reservation (especially if you have a small party)
-Also in NOS, is French Markey Restaurant (QS) It has a lot of great food, big portions, and, don't forget to get some: Mickey Beignets!!
-I suggest reading the "DLR for WDW veterans" thread, it helped a lot when I was attempting to plan my trip, other things to know, some of the rides will be different, longer, shorter, darker, wetter, you get the point.
-Splash mountain is single file line ridden, and there are no lap bars
-It will be CROWDED, but it's just the matter of figuring things out, and you'll be ok.
-The castle is smaller....way smaller...it doesn't feel the same at all walking down DLR's main street (to me at least)
-The fireworks at DLR are a not miss event!!
-The layout of DLR was a little weird for me, but that was because of ToonTown, which I never experienced at WDW, so it may be the exact same, who knows?
-World Of Color. You will die. It is amazing. I suggest on your DCA day, you follow the crowds and go straight in to get your WOC fast pass, then head straight to the next rope to head over to TSM (Edited to add: I see Kelliroo's post above me now, and I'm pretty sure that I read that they're not offering the dining package anymore/currently, I'm not too sure. I also don't think it really wastes time to get a fp, as the rest of the park isn't open yet, you're going from one rope to the next, but that's just me)
-TSM has no fast passes
-Tower of Terror's drops are the same every time, but the ride itself is different from DHS, and thus, the first couple of times you have no clue when you're going to drop.
-You guys just have WDW Ap's, right? If you have any kind of annual pass that works at DLR, every single time you buy food/merch, ask if there's a discount, I saved roughly $200 on food when I was down there thanks to my premium annual pass.
-I have a solo DLR trip report (pretty sure it's my signature) that might help some stuff if you wanted to check that out.
Have an awesome trip!!!