What's the difference between sport and exercise

What's the difference between sport and exercise

We often say "what is a very good sport" with sport, such as swimming is a good sport. We exercise with do exercise. Of course, exercise can also refer to exercise homework, such as English exercise

I do sports every day to be line
Why do you use "to" instead of "be" and "is" after the subject? Why is "I do sports every day is good" correct? Why is "she is sure to be the win" used?

Use the original form after the modal verb

Do you need shoes___ sports?We have lots of shoes___ very good prices A.for at B.for with

A
. for is "suitable for" at is "in. (price, speed, ratio)"