I haven't traveled with one that young, but it has been done by others. There will be challenges for sure, but I think you can still have a great time if you "prepare" for the unexpected.
I would go for it, but be prepared to take it really slow, as it sounds like you are. We took our first trip with an 18 month old and one "in the oven" at 33 weeks. We went for 5 days and only spent 2 days in the parks. We explored the resort and played in the pool during our other days. We didn't go to WDW again until the younger one was 13 months, but again we took it slow and also took grandparents for the extra hands. I think having the extra hands was a HUGE help with two kids as young as mine were, so you may want to consider that if it's an option.
I found FL was usually too hot to babywear, but I took our Ergo in the diaper bag just in case (we always used it in the airport anyhow, so i had it with us). I would also plan out air conditioning to keep the little one cool. Almost every bathroom is a nice place to cool off, even if you just stand in the doorway for a few minutes. Little ones in diaper layers with all those skin folds are just magnets for heat rash. Know where the baby care centers are and use them. They have a nice area where you can privately nurse if you need to, a huge changing room, and basic supplies if you are short on anything.
When ours were smaller we would plan for them to nap in the stroller (going back to the hotel for naps and returning later just weren't going to work for us). We would hop on the monorail and ride it in circles for an hour while they slept in the A/C. Or we would go down by the waterfall near Starlight Rays (MK) and they would sleep to the white noise of the water.
As for the rides, there are many that you will be able to do WITH the baby, and many others will offer rider swap. If you are just two adults you will have to ride alone while one stays with the baby, but the rider swap will allow you to both ride without having to wait in line twice.
I would plan to take it easy, be relaxed with your ADR planning. Either skip ADRs just in case you have to leave parks early and don't want to worry about skipping a reservation; or plan them early enough in your day that if you feel like leaving the park early you won't miss it. We would make our table service reservations for midday so that we had a nice chunk of time indoors during the high heat.
Rent a stroller from an outside company or bring your own so you can take it all the way back to your hotel. Disney strollers are not for infants and are super expensive. You'll want one that lays down completely for those times when baby gets sleepy. Get a fan for the stroller and find out from the pediatrician if you can use sunscreen on a baby that age. If not, make sure you have a way to keep the baby fully out of the sun.
Congrats on your new addition! Happy planning, and have fun!