Before April 2023 i spent 1 night camping out in the backyard with my then 3 year old son as a adult. Since them i have spend 15-20 nights camping/Backpacking with my kids scouts. Here are my tips
-At First keep it simple 1 night close maybe back yard, Have your kids gear be very warm, Last spring i camped with my Daughter(she was 7) and it diped into the 40s, she was over in my bag snugling in the middle of the night
-Keep them fed well, Snacks, easy foods to prepare so they eat, Camp outs arent the place to try need foods for the first time, Keep them well fed
-Kiss concept applies for everything, Keep it simple stupid, Dont over think it, Kids like to be kids, Your kids are currently younger but let them be kids, explore, snap branches get dirty by them selves when they are older
-As others said plenty of extra cloths layers ect, warm dry kids are happy kids, iv seen many campouts in my cub pack that the kids walks through mud and the parents didnt pack extra socks or shoes and they left early.
-Look at outdoor boys youtube channel at older videos, he camped with his youngers kids, from warm to cold, good ideas to take
-Most camping stuff will go on sale, Figure out what you need and buy it when on sale, Seirra trading post, Rei outlet, rokslide classified, Facebook marketplace
-Last when your kids get older look into scouting(they can join at kindergarten) it will keep them out doors with like minded people, The Bsa gets a bad rep from the wrongdoings of years past but its a good program.