During a Time When There is Peace and Happiness
The moral of the story is, get involved with them, get them active and have fun. After that, they are teachable. The biggest thing to avoid is telling them anything derogatory, because they will become more of what ever you call them and you don't want that. Also, a lot of the time all they want is your undivided attention, so give it to them in a good way. Later on, you can use the same momentum they exhibited while doing "world records" to get them to do chores.
As far as chores go, give them a choice of different chores to do. Let them pick. It changes their mind set and now they feel in control of something and you will have a lot more success. Remember, agency is what we all fight tooth and nail for so whenever possible in life, give them choices.
As far as tantrums go, I try my best to ignore them if it is at all possible. The best thing to do is deal with tantrums at home, so hopefully they get the worst of it out when you are not in public, but that is not always the case. I can tell a lot of stories of very public tantrums with my kids over the years, but the most important thing to remember is, they do turn into really awesome adults if you handle it right. If a child is throwing a tantrum at home, a timeout in a room where they are not the center of attention works wonders. Not a room full of stimulation either. I found the laundry room to be a great cooling off place. I would tell the child they need to remain in there until either they calm down, or a timer goes off, or both. Then, no matter what, do not give in to their demands. Consistency is the most important part of this. Do not give in no matter what.
This is one you have to win or else the tantrums will escalate. Believe me, you do not want to raise a child into a teenager that doesn't know how to control themselves. Teach them while they are young and when they are old they will not depart from it.
Realize that some tantrums, and whining, and laziness is just normal growing up. Do not seek for perfection because that will only frustrate you all. Everyone has good and bad days. Let your children be children and don't sweat the small stuff. Anything that you can possibly let them decide for themselves, let them. Pick your battles. Only fight and win on the battles that really really matter. And finally, find joy in the journey. Children are the most priceless thing in the world and they need your love and attention more than anything else.