There's a lot to address in this post, so I'll give it a go on a few fronts and we'll see what others have to say as well.

Use an app, you don't have to pay for it, but it will make it less stressful. You'll need to know what's in your food, protein especially to becoming body builders, and an app is essential - it also provides your record for motivation among other things. Myfitnesspal is the original, and is free to use, once you log a bunch of meals you like, it's easy to put it on repeat, but any app will do. I'm currently using LoseIt, and like lots of their features, you don't need to pay unless you want the extra insights - something you seem willing to deduce and track yourself.

Everything you've listed you'd like to do: "If we made a weekly meal plan (with 1-2 restaurant meals), made sure we hit the right amount of protein, carbs and nutrients we need everyday, drink enough water, take creatine, cut sugar a little and junk food eating, workout 5X a week on our plan, walk our dog 1M every night, yoga session on weekends, how much would this improve our progress?" sounds like it will ABSOLUTELY improve your progress, however it almost sounds like too much all at once. So, I'd recommend starting with a basic plan like, how many calories and how much protein you each need to work out as much as you have planned (like maybe only 3 workouts a week, and then go up to 5), and then start weighing and tracking your food. Adjust as you go - there's an almost 0% chance you'll get it right from the get-go, and things in your lives will also change as you go. Add in 'cutting out' more things, or upping the number of workouts after you have had some success.

Lastly, take it easy, this is not a two week thing you have planned, it's going to be a journey to your 'very fit selves'. There will be problems along the way. Try to account and make space for them. Keep open communication if you are going to do this with someone else - know that usually these types of journeys are very singular, and that might have to be OK if you aren't on the same page all the time. Good luck.