Parents what is your best cooking tip/trick for a single dad like me?

i'm a single parent of an already rambunctious baby girl and i've discovered that i'm rubbish in the kitchen. i've never had anyone else to take care of before and never learned to cook. I can make a ham sandwich and that's about it. Once I thought successfully made roasted chicken, then I cut into it and it was still frozen on the inside (don't try to cook a frozen chicken LOL)