M.B.
Heck, even for adults tacos are so easy!
You can do a lot of the prep ahead of time (shredding the lettuce, chopping tomatoes, etc), brown the ground beef, add the taco seasoning, and put it in a crock pot to keep it warm.
Everyone can fix it to their tastes... have plenty of hard shells and flour tortillas on hand (some prefer a soft taco). Other additions could be refried beans, queso and chips, salsa....