I find it easiest to just cook extra supper and then serve it the next day for lunch or freeze it for a quick meal when I need one. About once a month, I also take half a day and cook a few meals and freeze them. It's so much easier to just throw them in the oven and reheat when needed. Right now in the freezer I have turkey shepherd pies, fish and potatoes, mac and cheese with hot dog casseroles and beef stew. I just add to the meal if needed (veggie, starch etc)

I don't purposely make kid friendly meals as I want them to get used to eating "real" food but we do eat things like hot dogs, grilled cheese and chicken nuggets but it's not our usual. I do usually keep it simple though and just make sure each snack has 2-3 food groups and lunch has them all. They eat what we eat for the most part.

Pinterest has some good articles though on how to make some meals more kid friendlier.