We have 3 littles and for a first trip I would not do anything less than 4 days with littles!
You could do 3 days & get most everything in but may feel rushed the 3rd day and with 2 days & littles I would say you’ll end up skipping a lot & have no chance for repeats.
DCA is a great combination of HS and EP with a lot of it’s own flavor as well so you’ll probably want at least 2 days there if your girls like a lot of HS and EP. Plus it will allow you to repeat some of the absolutely wonderful attractions there.
DL is like MK with 2x the available attractions so if you like 3 days at MK you’ll definitely be able to fill in 2, if not 3 full days at DL. Especially with doing BBB one day. And speaking of BBB, I would get on booking that reservation as soon as you can confirm what days you’ll be in the parks. The reservations open up 60 days before and while I’ve been able to find availability the week-of, it’s been later in the day which I don’t prefer as I want as much time with DD in her made over hair & makeup & gown!
As for character meals, our favorite character meal is Goofy’s Kitchen in the Disneyland Hotel but the characters are definitely what you go for & less so the food, although I’ve only had better & better experiences over the last few times of going so it seems they upped their game on the food. If you go to Goofy’s request to sit in the circular room as there is better light for photos & more room in here, plus the characters all parade through here during the napkin-waving parade. We also like to get as late a reservation as possible for “breakfast” (which goes until noon or 1pm somedays) as we find the character interaction more lax & wonderful!
Another fantastic character meal that is convenient & chalk-full of characters is Plaza Inn. It’s like character speed-dining though & if you’re not used to a quick pace of characters can get frustrating to figure out when to go & get food. But you can get anywhere form 8-14 characters depending on what time you go (go earlier for more characters if that’s your aim) and some of those are characters only seen at Plaza & are otherwise considered rare. The food is decent too & again has seen improvement over the last few times I’ve done it vs. a few years ago when it felt more cafeteria-ey.
Also, the food at Storytellers at the Grand Californian is the best quality of buffet food offered at DLR & for that reason alone is my husband’s favorite. We haven’t been to it since the characters changed from “Critter Friends” to “Mickey & Friends” but I’ve only heard great things about the new characters & the outfits from pictures I’ve seen (including from @Ms.BarbsWildRide’s experience there) are just adorable! Another fantastic thing about Storytellers is that it’s so close to the entrance between GCH and DCA that it hardly feels like leaving the parks. You will have to re-do security to get back into the parks after Storytellers but after the initial hour or so of DCA opening that entrance isn’t usually too backed up so usually security is pretty smooth-sailing there.
As for what to do & what to skip in DL vs. WDW… check out my response to the following: First Disney Trip with Young Children! - #16 by lolabear_la. If you want to just skip to where I get to the attractions specifically, start from Must-Do’s Unique to Disneyland Resort, but that whole thread is a good collection of responses from me & some other pro’s on bringing kids for the first time so a good one to read in its entirety.
Any other specific questions you have, ask away! We love to help!!