Not a potential father, but a somewhat (2 yrs) experienced mother.

Get a good baby scale. It helped us realize that ours wasn’t gaining weight at 4-5 weeks, despite not acting like he was hungry (I breastfed), which prompted us to supplement with formula and me to pump more aggressively. He never really got into nursing, but I was able to pump most of what he needed, and my husband was game for doing the nighttime and wake up feeds and diaper changes while I pumped.

I rarely changed an overnight diaper. My husband was (and is) amazing.