Welcome! We bought a 351 this year after a few years of rentals as well! So far, it's been fantastic fun for us.
I don't have any suggestions on the toddler proofing(we only have cats!) but would highly recommend a few things
Buy a rhino flex sewer pipe if you haven't already.
Screen door bar from camco will make your life easier closing the door
Replace the mattress, it's awful. We ordered one from amazon for about $300 incl shipping
Make sure to buy a 50 to 30 and 50 to 20 amp plug converters
Lots of other suggestions, but those are my top ones! Also, there is a great place to store a broom and mop behind the sliding bedroom door.
Post in the georgetown forum, there are several families with small kids and I'm sure they have some good answers or suggestions for you. There are no dumb questions, and theses forums are great!
Happy travels!
Garren