Do it in groups according to leg strength.
Always do ... every day
exhaust
After the leg strength is enhanced,
Straighten one leg.
Parallel to the ground
Do squats with one leg
You may not have a good balance at first.
Hold the table or chair first.
Do it alternately. Legs: first find a ladder or a book to pad your feet, then put your toes just on it, and your heels are not allowed to touch the ground or the mat.
Lift your toes to the highest point, and then slowly put them down.