i'm 17 yrs old and i'm 5'7. How do you get taller naturally ?

How tall a person is and when they stop growing is coded into their DNA. Most, but not all, people are done growing by age 17. the only way to know if YOU can still grow is to have an x-ray of your growth plates. Once these bones fuse closed, your bones can't grow, so you won't get taller. As long as your growth plates are open or "soft" you could grow. It doesn't mean you will, but the possibility is there.

Proper nutrition during childhood and puberty increase the likelihood that a person will reach their personal maximum height, but that won't make a person destined to be 5'8" grow to be 6'4".

By planting yourself firmly in soil watering yourself generously, lol. Sorry, I couldn't help myself, lol.

Your height is what it is, you can't change it.