Frist off take a breath... Okay, lets do that again....
that's Better... It is very overwhelming planning even for a experienced planner.
Frist tip - You are not going to be able to see it all and do it all...Repeat as necessary..
For your first trip, or any trip really look at the make of your family, add in nap times, with a toddler and a baby you will want them to stick to a normal schedule as possible. Celebrations birthday, anniversary's or some other life moment. I would plan some down time, pool time and possibly a nap for everyone. This gives everyone time away from all the excitement and all the over stimulation.
I would try to plan on 1 TS a day, just to regroup, get off your feet, and in the air conditioning. I would plan on 1 character meal if you are paying out of pocket, if your on the dinning plan you could add in some more.
Do a lot of homework when it comes to the menu's, not only table service (TS) but quick service (QS). There is nothing worse than heading in some where to eat with a hungry family or worse a hangry family and finding out that nothing on the menu is going to work.... Also if anyone has some type of food allergy Disney is the best at helping you, make sure to put it on dinning reservations, and if not sure ask at the QS, they have a book so you can be sure.
I would let everyone pick out a favorite ride, and do those first... yep mom and dad get to pick to... When making your FP's get the ones you really want 1st, start on one side of the park moving from land to land.... to the other side, a lot of crisscrossing the parks is wasted time and steps... So spend some time getting to know your maps...
Use photo pass... That way everyone can be in all the pictures it is your 1st trip... Special Memories.
Stop and smell the roses so to speak, just grab some mickey bars and sit down some where shaded and just take it all in....
For the little kids bring the big stroller trust me when I tell you that you will need it.
Bring lots of snacks, snacks are really costly.... Get a small softside cooler to take into the park, for water, juice boxes, fruit, cheese sticks, soda.
Rule of thumb is 3 to 4 bottles of water per person per day not including meal times... Since your driving this will be easier. You will be surprised at how much water you need to drink, keep everyone hydrated. You can get free ice water in the QS restaurants.
You can also meal share, to save money and not be wasteful... Disney portions are huge and easily shareable. You can share at TS just let the server know you want to share, a lot of times they will divided it up in the kitchen some times they will bring you a extra plate. Please tip as if everyone was ordering a entrée.
The more homework you do now, the better off you'll feel when you arrive...
Wishing you and your family a Magically Adventure...