My DH and I took our 4 month old to disney...we were also 1st time parents but are veteran disney goers so we werent nervous at all. We knew Disney was probably the one place where we could go with such a young baby and have a great time!
Here is what we did:
*Shipped a box of baby essentials to resort (diapers, wipes, baby soap, baby sunblock...anything we needed in bulk)
*Made sure we had a fridge in room to store her milk/food.
*Utilized all Baby Care Centers in the parks. They are a lifesaver. They all have changing tables, bathrooms, nursing rooms, filtered water cooler, microwave, a place to sit and feed baby in the air conditioner and they sell everything baby related from diapers to baby tylenol to baby food etc.
*We used the Baby Bjorn carrier and it was great to just walk on all the rides with her attached to one of us.
*We brought our usual everyday stroller so she would be comfy and we bought the rain cover and bug cover. The rain cover was the best thing we bought. Saw so many kids in strollers just covered in a cheap poncho getting soaked while our baby and stroller were totally protected and it even had air vents in the sides! Didnt use the bug cover once.
*Let her nap when she needed and took it easy.
*The loud fireworks scared her but all of the rides were fine..she went on everything except roller coasters.
*Restaurants allow you to bring in stroller...especially while baby is sleeping. They always gave us a table in the back with room for stroller. They also always gave me bowl of hot water to warm bottles etc.
*Disney hotels have pak-n-play cribs for you to use for free. Bring your own sheet as the Disney ones can get grungy. They also have highchairs that can be brought to your room.
*Bring lots of changes of clothes for baby and always a tshirt for you and hubby...my daughter had a habit of throwing up on us so it was great to have an extra shirt stored in our stroller to change into instead of going back to hotel or buying one which are $$$.
Hope this helps! Cant think of anything else!
Have fun and enjoy every second!!