We took DD when she was 2 and twice when she was 3. Those were actually my favorite trips as everything was new and magical to her. Flexibility is key. I think you don't know how they are going to react and what works for them until you are actually there for your first trip.
Do you have a time change to deal with? That can impact things.
We had heard on there that afternoon breaks/naps were key and that was our plan. That was not DD's plan. On the whole, DD was much better behaved at WDW than at home as she was really happy. The afternoon break the first day of our trip was the one major fit she threw that trip. We dragged an angry child out of MK and watched her stand behind the curtain of the room so angry she did not even want to look at us, and refused nap for 2 hours until we finally gave up and went back to MK. She got a giant smile on her face when we got back to MK and immediately climbed in her stroller and took a nap. After that it was stroller naps in the park for us all of her pre-school years. It worked great for us. We went pretty much open to close and she just got in the stroller and napped a while when she was tired. DH and I could take turns single rider or back then (FP) on big rides while she slept.
For us--- we found that table service lunches worked better than table service dinners. We would have a few hours in the parks- then lunch would be a break and would wind her down to nap in the stroller after. We found her to be a little more tired and restless at table service dinners.
We did the Christmas party when she was 2 (and free at that age) and also when she was 3, and those were the highlights of our trip. She loved all the characters, and just the atmosphere in general. We had a one hour time change which probably helped-- and DD was always a bit of a night owl.
We did find Christmas (and Halloween) party days less crowded in the mornings at MK. The crowds quickly pick up at 4:00 when they start letting party guests in. The first few hours those mornings are really nice.
You never know what is going to suddenly catch their interest and be extremely important to them at that age. Be ready to be flexible depending on what it turns out they like or don't like, and what works or doesn't work for them. Mine loved all the characters- that was her main focus. Does your child like live characters or find them scary? If we saw a line was really long we had a distract and block system to keep her from seeing the character meet at all, because otherwise she was going to want to be in that line. Also, be ready for the requests for repeat rides on things--- mine loved Small World and Peter Pan (re-rides are difficult on that one with the long lines and current system), and we had to have a 5 ride in a row cut off for the boat ride in Mexico or she would have gone in circles all day. Also, don't underestimate the appeal of Living with the Land- for some reason, most of the 2 year olds we know that have been love that ride. My dream was to walk into the parks and have DD mesmerized by the castle and then go straight to Dumbo. I was so excited to take DD on Dumbo and it was where I planned to head first our first day. DD walked into MK, didn't give the castle a second look and as I was attempting to rush to Dumbo, spotted Pluto and we were completely diverted as she HAD to meet him (and it was magical when we got to the front of that line). When we got to Dumbo- she took one look, pointed up and said "I not ride him". Never got her on him that trip. We later found out she was scared of heights- we had no idea--but she would ride the Aladdin Carpets because her love of Aladdin was stronger than her fear of heights. So, just be ready to pivot if it turns out your child doesn't like what you thought they would, or wants to do something different than you planned. DD's 2 year old trip, we planned to have pool time and the weather was hot that year, but DD had no interest in the pool at all. She wanted the parks. She was not a morning kid and it has always been hard to get her up and moving in the mornings-- but once she was awake and dressed she was standing at the door in the hotel room telling us to hurry up so she could get to the park and she didn't want to leave to go back to the pool. We would ask if she wanted to back to the pool and swim and got a firm "NO-- we stay here". I also would recommend trying for rope drop- but not stressing if you don't make it- and with that age unless you have a specific reason (I can recall an Anna/Elsa run for us at
Disneyland back when they were new and hugely popular)- not worrying about getting there way before the gates open. We typically got to the parks right around rope drop or within the first 20 to 30 minutes the park was open. The afternoons do get crowded and the mornings are usually better, so early is good if you can make it work.
Also, we have been the same week you are going multiple times. Do not count on pool time at all- you may or may not have the weather for it. The weather is crazy that time of year. Pack for anything. DD's 2 year old trip, the weather was predicted to be in the low 70s every day so we packed for that-- there was a heat wave the 2nd day and the temperature was around 85-90 with some days having record highs the rest of the week. Would have been a great trip for the pool- but she had zero interest in the pool. One time we went your week, the highs were in the 50s and maybe some low 60s and we were in sweaters all week. Another time we started the week in shorts and t-shirts and ended the week spending all day in sweaters with coats over them. You just never know what you are going to get that time of year and it changes fast. Check the weather the day before you go from the local channels online and then still pack for everything because the forecast isn't always right.
Have a great trip!!!!